T N 

+ 03 


T 

i 



VORTH CAROLINA GEOLOGICAL AND 
ECONOMIC SURVEY 


Joseph Hyde Phatt, Director, 


BULLETIN No. 32 


MAGNETIC IRON ORES OF EAST TENNESSEE AND 

WESTERN NORTH CAROLINA 


BY 


W. S. BAYLEY, Geologist. 


Prepared by 

North Carolina Geological and Economic Survey 

and the 

Tennessee Geological Survey , 

as a joint report 


-I'- 


! V' 


In cooperation with the 

United States Geological Survey. 


1923 . 





Glass 

Book 






1 




9 


i 




/ 

NORTH CAROLINA GEOLOGICAL AND 

♦ 

ECONOMIC SURVEY 


Joseph Hyde Pratt, Director. 


T6 



BULLETIN No. 32 


MAGNETIC IRON ORES OF EAST TENNESSEE AND 

WESTERN NORTH CAROLINA 


W. S. BAYLEY, Geologist. 


Prepared by 

North Carolina Geological and Economic Survey 

and the 

Tennessee Geological Survey 

as a joint report 



In cooperation with the 

United States Geological Survey. 


1923 . 






jUU^' 9W 


ytfilON 


M 

i 



GEOLOGICAL BOARD 


Governor Cameron Morrison, ex-officio Chairman 

Raleigh 

Frank R. Hewitt, 

Asheville 

C. C. Smoot, III. 

North Wilkesboro 


John H. Small 
Washington 

S. W estray Battle 
Asheville 


Joseph Hyde Pratt, Director 

Chapel Hill 


LETTER OF TRANSMITTAL 


To His Excellency , Cameron Morrison , 
Governor of North Carolina. 


Chapel Hill, N. C. 
April 1, 1923. 


Sir: 

The North Carolina Geological and Economic Survey has prepared 
in cooperation with the Tennessee Geological Survey and the United 
States Geological Survey, a detailed report on The Magnetic Iron Ores 
of East Tennessee and Western North Carolina. This is the second 
report that the Survey has prepared in cooperation with the Survey of 
a sister State, the first report being on the Yirgilina Copper District in 
cooperation with the Virginia Geological Survey. 

As the problems that had to be considered and solved in connection 
with these magnetic iron ores were joint problems it was felt that better 
results could be obtained if the investigations v T ere carried on coopera¬ 
tively by the two Surveys and that the field w ork in both States be done 
by the same geologist. Prof. W. S. Bayley was employed by the two 
Surveys and has done all the field work, with the approval of the Direc¬ 
tors of the two State Surveys and of the United States Geological Sur¬ 
vey. 

The report is a geological and economic investigation of these 
magnetic iron ores, and it is recommended that it be published as Bul¬ 
letin 32 of the reports of the North Carolina Geological and Economic 
Survey. 

Yours respectfully, 

Joseph Hyde Pratt, Director. 

North Carolina Geological and Economic Survey. 


CONTENTS 

Foreword. 10 

Preface and summary. 11 

Chapter I. 

General considerations. 17 

Magnetites and titaniferous magnetites. 18 

Composition and classification. 18 

Occurrence. £0 

Hematitic magnetities. 22 

Chapter II. 

Historical review of literature. 23 

Chapter III. 

The ores. 35 

General features. 35 

Magnetites. 36 

Chanter IV. 

i. 

Siliceous magnetites. 37 

Character. 37 

Deposits in the mountain districts. 37 

Geology. 37 

Roan gneiss. 39 

Bakersville gabbro. 41 

Cranberry granite. 44 

Relations between Roan gneiss, Cranberry granite and other rocks ... 47 

Ore veins. 48 

Vein-filling. 48 

The ore. 52 

The gangue. 58 

Pegmatite. 62 

Gneisses. 64 

Relations ox the rocks in the vein-mass. 66 

Age. 67 

Origin. 68 

Utilization. 69 

Reserves. 76 

Chapter V. 

Exploration. 82 

Preliminary statement. 82 

Instruments employed in exploration. 82 

The dial compass. 82 

The dip needle. 88 

The magnetometer. 91 

Sampling. 92 

Chapter VI. 

Mines and prospects in siliceous magnetites. 97 

General features. 97 

Carter County, Tenn., and Avery and Mitchell counties, N. C. 97 

The Cranberry belt. 97 

Cranberry mine. 98 

General description of mine and ore. 98 

Smoky No. 1. 106 












































4 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Smoky No. 2. 108 

Firmstone opening. 112 

Mine opening. 112 

Other openings in the Cranberry belt. 117 

Lee Johnson place. 117 

Cooper place. 118 

Ellers and Hardigraves Elk Park openings. 118 

Wilder mine. 119 

Greenlee and Ray and Tester property. 122 

Red Rock mine. 122 

Patrick mine. 123 

Teegarden and Ellis mines. 123 

Heupscup Ridge prospects. 126 

Peg Leg and Old Forge mines. 126 

Horse Shoe prospect. 128 

Julian prospect. 129 

Campbell prospect. 129 

Chestnut Ridge prospects. 130 

Magnetic City prospects. 130 

Deposits between Magnetic City and Toe River. 131 

Madison County, N. C. 132 

Big I vy mine. 132 

Chapter VII. 

Mines and prospects in siliceous magnetites. 134 

Alleghany and Ashe counties, N. C. 134 

General statements. 134 

Kirby opening.. 136 

Deposits in the Poison Branch belt. 139 

General description. 139 

Pugh and Smith openings. 139 

Deposits on Helton Knob. 140 

Blevins openings. 140 

Red Hill openings. 141 

McClure's Knob deposits. 142 

Poison Branch mine. 143 

Openings between Silas and Piney creeks. 145 

Piney Creek opening. 146 

Francis and Henninger openings. 147 

Openings on Turkey Knob. 148 

Graybeal property. 149 

Waughbank property. 153 

Hampton Knob openings. 153 

Openings southwest of Hampton Knob. 153 

Openings southeast of Lansing. 154 

Deposits in the New River belt. 155 

General description. 155 

Openings in Alleghany County. 155 

Lunceford openings and Cox place. 156 

Brown openings. 157 

Ballou Home Place and Sand Bank openings. 157 

Reserves in Ashe County. 160 




















































CONTENTS 


O 


Chapter VIII. 

Mines and prospects in siliceous magnetites. 161 

Deposits in the Piedmont area of North Carolina. 161 

Preliminary statement. 161 

Origin. 163 

Reserves. 165 

Catawba and Lincoln counties, N. C. 166 

General description. 166 

Deposits in the Catawba-Iron Station belt. 166 

Pow r ell ore bank. 168 

Little Mountain deposits. 168 

Anderson Mountain openings. 169 

Morgan and Stonew all banks. 169 

Brevard and Big Ore banks. 170 

Deposits near Iron Station. 172 

Deposits in the Newdon belt. 172 

Barringer mine. 172 

Forney and Killian mines. 173 

Exposures on Howards and Indian creeks. 174 

Deposits in the Eastern belt. 175 

Gaston County, N. C. 175 

General statements. 175 

Deposits in the Eastern belt. 176 

Crow r ders Mountain deposits. 176 

Deposits in the Costner mine belt. 177 

Costner mine. 177 

Ellison mine. 178 

Ferguson mine. 178 

Fulenwider mine. 180 

Yellow Ridge mine. 181 

Chapter IX. 

Marble magnetites. 183 

General character. 183 

Ashe Mining Company’s mine. 183 

Chemical and mineralogical composition of ore. 184 

Association of minerals in the ore-mass. 188 

Pegmatite veins in the ore. 191 

The ore-body. 192 

Other marble-magnetite ores. 194 

Pit on Dr. Jones’s property. 194 

Red Rock mine. 194 

Origin. 195 

Production and reserves.. 196 

Chapter X. 

Titaniferous magnetites. 198 

Characterization. 198 

Distribution. 198 

Composition. 199 

Origin. 205 

Utilization. 207 

Reserves. 208 



















































6 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Chapter XI. 

Mines and prospects in titaniferous magnetites. ^09 

General statements. ^09 

Deposits in the mountain districts. ^09 

Ashe County, N. C. ^09 

Distribution. ^09 

Smith place. ^10 

McCarter place. 215 

Bauguess place. 215 

Pennington opening. 216 

Alleghany County, N. C. 217 

Avery and Mitchell counties, N. C. 217 

Distribution. 217 

Senia deposit. 218 

Avery place. 219 

Grassy Bald of Roan Mountain. 219 

Jenkins prospect. 220 

Other deposits. 221 

Carter County, Tenn. 222 

Lost Cove prospect. 222 

Other deposits. 223 

Yancey County, N. C. 223 

Madison County, N. C... 224 

Macon County, N. C. 225 

Dobson Mountain. 225 

Other deposits. 226 

Chapter XII. 

Mines and prospects in titaniferous magnetites. 228 

Deposits in the Piedmont area, North Carolina. 228 

Preliminary statement. 228 

Caldwell County, N. C. 228 

Farthing place. 228 

Richlands Cove. 229 

Rockingham, Guilford and Davidson counties, N. C. 230 

Tuscarora and Shaw belts. 230 

Tuscarora and Dannemora mines. 234 

Shaw mine. 237 

Apple plantation. 238 

Davie County, N. C. 238 

Chapter XIII. 

Hematitic magnetites.*. 240 

Deposits in North Carolina. 240 

Deposits in Tennessee and adjacent portions of Watauga County, N. C.. 241 

Deposits in the valley of Laurel Creek. 241 

Whitehead prospect. 241 

School House prospect. 241 

Deposits in Walnut and Beech mountains. 242 

Big Ridge openings. 242 

Explorations near Elk Mills. 242 

Deposits on Lunsford Branch. 244 

Scrawl Ridge openings. 244 

Lunsford prospect. 244 

Finney and Teegarden mine. 245 

Origin. 251 

Reserves. 252 





















































CONTENTS 


7 


ILLUSTRATIONS 

Plate Page 

I. Map showing principal mines and explorations on and near the 

Cranberry belt, in Avery and Mitchell counties, N. C. 34 

II. ( A ) Photomicrograph of Bakersville gabbro, near Cranberry, N. C... 43 

( B ) Photomicrograph of ore from Peg Leg mine. Carter County, Tenn. 43 

III. Polished surface of portion of vein-filling, Cranberry mine, Cran¬ 

berry, N. C., showing interlayering of ore and gangue. 49 

IV. Polished surface of portion of vein-filling, Cranberry mine, Cran¬ 

berry, N. C., showing association of ore with hornblende. 51 

^ . Polished surfaces of two specimens of pegmatite and ore, from vein 

at Cranberry mine. Cranberry, N. C. 53 

VI. (.4) Photomicrograph of lean ore, Cranberry mine, Cranberry, N. C. . 55 

(B) Photomicrograph of schistose ore from Teegarden mine, near Shell 

Creek, Carter County, Tenn. 55 

VII. ( A ) Photomicrograph of garnetiferous magnetite ore, from Smoky No. 1, 

Cranberry, N. C., in ordinary light. 57 

• B) Same as A, between crossed nicols. 57 

VIII. (A) View of pegmatite and ore in wall of open cut. Cranberry mine. 

Cranberry, N. C. 59 

(B) View of younger pegmatite cutting across ore vein in Teegarden 

mine, near Shell Creek, Tenn. 59 

IX. Polished surface of pegmatite streaks in vein-filling, Cranberry 

mine. Cranberry, N. C. 01 

X. (.4) Photomicrograph of epidotized pegmatite vein-filling, Cranberry 

mine, Cranberry, N. C. 03 

( B ) Photomicrograph of pyroxene-magnetite pegmatite, Cranberry 

mine, Cranberry, N. C. 03 

XI. (A) Photomicrograph in ordinary light of epidote-hornblende gneiss, 

vein-filling, Cranberry mine. Cranberry, N. C. 05 

( B ) Same as A, between crossed nicols. 05 

XII. View of Cranberry mine, Cranberry, N. C. 99 

XIII. V iew toward Smoky Mountain, Cranberry, N. C. 101 

XIV. Cranberry Furnace, Johnson City, Tenn. 103 

XV. Map of surface, Cranberry mine, Cranberry, N. C., with projec¬ 
tion of underground workings. 105 

XVI. Plat of workings. Cranberry mine, Cranberry, N. C. 107 

XVII. (A) View of Smoky No. 1 opening, showing hanging-wall granite, Cran¬ 
berry, N. C. 109 

(B) View of part of wall, open cut, Cranberry mine, illustrating irregu¬ 
lar distribution of the ore. 109 

XVIII. ( A ) View of wall of open cut, Cranberry mine, Cranberry, N. C., show¬ 
ing irregular distribution of pegmatite in the vein-filling. 113 

(B) General view of wall of same cut, showing hanging-wall of foliated 

Cranberry granite. 113 

XIX. Isodynamic chart of Wilder mine property, near Shell Creek, Car¬ 
ter County, Tenn. 121 


























8 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


XX. ( A ) Photomicrograph of magnetite ore, from Kirby exploration, Stur¬ 

gill, Ashe County, N. C. 137 

( B) Photomicrograph of hornblende granite ‘horse' in Cranberry vein, 

showing epidotization of plagioclase. 137 

XXI. Polished surfaces of marble-magnetite ore from Ashe Alining Co.’s 

mine, Lansing, Ashe County, N. C. 185 

XXII. {A) Photomicrograph of titaniferous magnetite, from Smith exploration, 

showing alteration of ore mineral into rutile. 201 

( B ) Photomicrograph of silicates associated with titaniferous magnetite 

of Pennington exploration, Ashe County, N. C., showing prob¬ 
able pseudomorph after olivine. 201 

(C) Photomicrograph of titaniferous magnetite from Pennington ex¬ 

ploration, Ashe County, N. C., showing presence of rutile in the 
ore mineral. 201 

( D) Polished surface of ore, Tuscarora mine, Guilford Co., N. C. 201 

XXIII. (A) Photomicrograph of titaniferous magnetite from Smith exploration 

Ashe County, N. C., showing cracked magnetite. 211 

( B ) Photomicrograph of another part of the same ore, showing rutile 

in magnetite. 211 


Figure Page 

1. Index map of western North Carolina and East Tennessee, showing positions 

of detail maps. 20 

2. Dial compass. 83 

3. Diagram illustrating horizontal deflection of compass needle caused by buried 

magnetic strip. (After Smyth). 84 

4. Diagram illustrating effect of strike of magnetic strips upon needle of dial 

compass. (After Hotchkiss). 85 

5. Dip needle. 88 

6. Contour map of dip needle deflections over a band of magnetic ore. (After 

Broderick). 89 

7. Diagram illustrating effect of buried magnetic strip upon dip needle at dif¬ 

ferent positions. (After Hotchkiss). SO 

8. Diagram illustrating use of dial compass and dip needle to trace a magnetic 

line. (After Hotchkiss). 90 

9. Magnetometer. 91 

10. Map showing isodynamic lines over a belt of magnetic formation in a rough 

country. (After Smyth). 92 

11. Map of isodynamic lines over a series of magnetic lenses illustrating use as a 

guide for drilling. (After Hamilton). 94 

12. Diagram to illustrate how the meandering of a drill hole may result in missing 

ore-body. (After Hamilton). 95 

13. Map showing locations of magnetic iron ore deposits in Ashe County, North 

Carolina. (After Nitze). 134 

14. Sketch map of openings at Poison Branch Mine, Ashe County, North Caro- 

Carolina. (After Nitze). 144 

15. Map of portion of Ashe County, North Carolina, showing positions of the 

Graybeal property and the Ashe Mining Co.’s mine near Lansing. 15 ) 

16. Map of explorations on Ballou and Calloway properties, Ashe County, North 

Carolina. 158 




























CONTENTS 


9 


Figure Page 

17. Map of iron ore deposits in Catawba, Lincoln, and Gaston counties, North 

Carolina. (After Kerr, Hanna and Nitze). 161 

18. Ideal section illustrating shapes and positions of ore-bodies in Lincoln County, 

North Carolina. (After G. B. Hanna). 168 

19. Map of openings at Big ore bank, Lincoln County, North Carolina. (After 

Bailey Willis). 170 

20. Plan and section of Ashe Mining Co.’s mine at Lansing, Ashe County, North 

Carolina. (By Geo. W. Cooke). 186 

21. Sketch of marble exposures at Intermont, Mitchell County, North Carolina. . 196 

22 . Sketch map of northern portion of iron-ore belt in Guilford and Rockingham 

counties, North Carolina. (After Lesley). 230 

23 . Sketch map of southern portion of iron-ore belt in Guilford and Rockingham 

counties, North Carolina. (After Lesley). 231 

24 . Openings at the Tuscarora Iron Works, Guilford County, North Carolina. 

(After Bailey Willis). 232 

25 . Plan and sections at Danemora mine, Rockingham County, North Carolina. 

(After Bailey Willis). 233 

26. Map of explorations on Walnut Mountain, near Elk Mills, Carter County, 

Tennessee. (After Keith and Hamilton). 243 

27. Diagrammatic cross section through Finney and Teegarden mine. Carter 

County, Tennessee. 245 

28. Photomicrograph of hematitic magnetite ore from Finney and Teegarden mine. 

Carter County, Tenn. 247 













10 


MAGNETIC IRON ORES OF EAST TENN. AND AVESTERN N. C. 


FOREWORD 


The present report, entitled “Magnetic Iron Ores of East Tennessee 
and Western North Carolina,” represents a joint investigation of an 
important magnetic iron ore district lying partly in each State, and which 
has been carried on cooperatively by the North Carolina Geological 
and Economic Survey, the Tennessee Geological Survey, and the United 
States Geological Survey. 

Professor W. S. Bayley, of the University of Illinois, Avas selected 
as the geologist to make the surA^ey in these tAA 7 o States, and during the 
course of investigation he has had conferences AA T ith the State geologists 
of North Carolina and Tennessee and with E. F. Burchard, geologist 
of the United States Geological Survey in charge of iron. 

The area coA^ered by the investigation includes Carter County* 
Tennessee, and parts of Ashe, Allegheny, Avery and Mitchell counties* 
North Carolina. 

The report also considers briefly deposits of magnetite in CataAA r ba, 
Lincoln and Gaston counties, North Carolina. The topographical maps 
Avhich have been used as bases of the geological maps accompanying this 
report Avere prepared from the topographic quadrangles of the Lmited 
States Geological SurA r ey and by special mapping of portions of the 
area. 

The United States Bureau of Mines has made the tests in regard to 
method of separation of the magnetites, using for this purpose samples 
of ore from the Cranberry mine, Avery County, North Carolina, col¬ 
lected by Professor Bayley and Mr. Burchard. 

The author has been very materially assisted by the owners of the 
various iron properties, and others interested in the general region, 
and the state geologists desire to make grateful acknowledgement at 
this time to all who assisted in various ways in facilitating the work 
of this investigation. 

W ilbur A. Nelson, 

State Geologist for Tennessee. 

Joseph Hyde Pratt, 

State Geologist for North Carolina. 


PREFACE AND SUMMARY 


11 


Preface and Summary 

The purpose of the study of the magnetic iron ores of East Ten¬ 
nessee and Western North Carolina was to learn, if possible, something 
of their value as a source of supply to furnaces in the South. It was 
undertaken at the suggestion of the State Geologist of North Carolina 
because the existence of the large deposit at Cranberry had led many 
persons to suppose that there might be other similarly large deposits 
in other portions of the mountain district. It was learned, however, 
soon after the beginning of the field work, that the most promising un¬ 
developed deposits are in the extension of the Cranberry vein in Ten¬ 
nessee and that the topography of the region in which most of the mag¬ 
netites occur is such as to make Johnson City, where there is already 
a modern blast-furnace, the natural outlet of the ores. 

I he furnace at Johnson City has utilized the ores of the Cranberry 
mine. It is desirable to learn whether or not there are other sources 
from which it may receive supplies. Rumors have been prevalent that 
there is an inexhaustible supply of iron ore in the area contributary to 
Johnson City. It is important to knoAv whether the rumors are well 
founded or not. These considerations led to the cooperation of the 
Tennessee Geological Survey in the publication of the results of the 
study—and the outcome is the present bulletin. Throughout the 
course of the study the U. S. Geological Survey cooperated with the 
two State Surveys, paying a large share of the expenses of the field 
study. 

%j 

Three 1 articles dealing with special phases of the subject, and a 
fourth 2 giving a summary of the entire study, have already been pub¬ 
lished. 

The field work on which the report is based was done during parts 
of the summers of 1919, 1920, and 1921. In 1919 about seven weeks 
were devoted to the study of the magnetite deposits of Avery and Ashe 
counties, N. C., and that portion of Carter County, Tenn., contiguous to 
Avery County, and about two weeks to visiting the deposits in the Pied¬ 
mont area of North Carolina. In 1920 the openings in the Cranberry belt 
of deposits extending westward from Cranberry into Carter County 
were again visited, about two weeks being spent in the study of critical 
areas, and a week in Ashe County making a topographic map of the 
region around Lansing and in the vicinity of the explorations on the 
North Fork of New River. In 1921 the region was revisited in company 
with Mr. E. F. Burchard of the U. S. Geological Survey. A number of 
the most important deposits were again examined and the Cranberry 

iThe magnetic ores of North Carolina—their origin: Econ. Geol., vol. 16, p. 142, 1921. 

A magnetite-marble ore at Lansing, N. C.: Jour. Elisha Mitchell So., vol. 37, p. 138, 

1922. 

The occurrence of rutile in the titaniferous magnetites of Western North Carolina and 
Eastern Tennessee: Econ. Geol., vol. 18, p. 382, 1923. 

3 General features of the magnetic ores of Western North Carolina and Eastern Ten¬ 
nessee: U. S. Geol. Surv. Bull. 735-G, 1922. 



12 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

mine was sampled for an experimental study of the susceptibility of its 
ore to magnetic separation methods. At the close of the season a day 
was spent examining the deposits of hematitic ores in Carter County 
between Shell Creek and Butler. 

The writer wishes to express his appreciation of all the courtesies 
extended to him by the people with whom he was brought in contact 
during this work. Not only did the dwellers in the district respond 
willingly to all his requests for information, but in many cases they went 
out of their way to aid him in the search for the hidden mine holes and 
exposures. Special thanks are due to Mr. F. P. Howe, President, and 
to the general officers of the Cranberry Furnace Company and to Mr. 
S. H. Odom, Superintendent of the Cranberry mine, for information 
that could not have been secured elsewhere, and for the use of maps 
of the Cranberry mine, and to Mr. George Cooke, President of the 
Ashe Mining Company, who served as guide to many of the explorations 
and exposures in the neighborhood of Lansing. Grateful mention 
should also be made of Messrs. L. W. Fischel and L. J. Phipps, students 
of the Lffiiversity of North Carolina for their painstaking work on the 
map portions of Ashe County. The writer is also under obligation to 
Mr. S. H. Hamilton from whose report, now in the possession of the 
Tennessee State Geological Survey, he has taken the description of a 
few deposits which were not visited, and has copied the magnetic map 
of the Wilder Mine. Finally thanks are due in large measure to Col. 
Joseph Hyde Pratt, State Geologist of North Carolina and Mr. Wilbur A. 
Nelson, State Geologist of Tennessee, for their generous cooperation 
with him during the prosecution of the investigation. 

The principal results of the study may be summarized as follows: 

(a) The magnetic ores contributory to Johnson City and those in 
the Piedmont area of North Carolina are of three types, viz.: hematitic 
magnetites, titaniferous magnetites and non-titaniferous magnetites, 
all of which are in rocks of pre-Cambrian age. 

The first group is composed of small deposits scattered over the 
mountain district of the two States. The largest and most character¬ 
istically developed are in the northeast portion of Carter County, Tenn., 
on Lunsford Branch between Butler and Shell Creek. They are asso¬ 
ciated with old volcanic rocks that may be classed with Keith’s meta- 
rhyolites 1 which are thought to be of Algonkian Age. These are asso¬ 
ciated with chloritic schists that are probably metamorphised basic 
volcanics. Both acid and basic rocks are saturated with fluorite. 
Magnetite and hematite are so closely incorporated with the chloritic 
schists that it is thought iron emanations accompanied the basic mag¬ 
mas to their present positions, and formed the ores. It is possible that 
the presence of hematite is due to the presence of fluorine in the emana¬ 
tions. 


‘Keith, Arthur, U. S. Geol. Surv. Geol. Atlas, Cranberry folio (No. 90), 1903. 



PREFACE AND SUMMARY 


13 


At present the hematitic magnetites are not of practical importance 
as sources of iron-ore since the quantity available in the district is too 
small to warrant the expenditure of the funds necessary to place it on 
the railroad. 

b. The titaniferous magnetites are present in the mountain dis¬ 
trict and in the Piedmont area. Some of the deposits are comparatively 
large, but most are too small to be of present value as sources of ore, 
even if they were acceptable to the furnace men. So long as there is a 
sufficient supply of non-titaniferous ore available there will be no de¬ 
mand for the titaniferous ore as a source of iron. In the future, when 
the supply of high-grade non-titaniferous ore is exhausted the titan¬ 
iferous ores will unquestionably become of importance. At present 
it would be necessary to separate from them concentrates nearly free from 
titanium before they could be utilized in the blast-furnace in competi¬ 
tion with non-titaniferous ores. This is possible in the case of some of 
them, but is so expensive that it is not practicable. 

Singewald 1 had shown that for the most part the titanium in these 
ores is due to an intricate growth of some titanium mineral with magne¬ 
tite. He supposed the titanium mineral to be ilmenite in such small 
plates and needles that it could not be separated by magnetic methods 
from the magnetite without such fine grinding that the cost of concen¬ 
tration would be prohibitive. Analyses of some of the titaniferous ores 
indicate that the titanium is not always present as ilmenite but that in 
some cases, at least, it occurs as an oxide and the study of thin sections 
show that much, if not all, of the titanium is present as rutile. How¬ 
ever, the discovery of this fact does not modify Singewald's conclusion 
that the ores are unavailable at present as sources of iron. In one 
group of deposits—that on the Tuscacora and Shaw belts in Rocking¬ 
ham, Guilford and Davidson Counties, N. C., the intergrowth may be 
coarse enough to warrant an attempt at concentration, but the deposits 
are so far away from blast-furnaces that they are not now probable 
sources of ore. 

In the field the titaniferous magnetites can usually be recognized 
by the fact that they are associated with basic rocks like gabbro. They 
are believed to consist mainly of segregations of ore minerals that were 
intruded into cooled portions of the same magma from which they were 
segregated. 

c. The non-titaniferous magnetites are the most promising sources 
of ore for the North Carolina and East Tennessee furnaces. They 
are very low in phosphorus, sulphur, and titanium and consequently 
are utilized for making a very low-phosphorus iron. The ore that 
has not been concentrated by magnetic processes is comparatively 
low in iron, rarely reaching a content higher than 41 per cent. It is, 

‘Singewald. J. T., Jr., U. S. Bur. Mines Bull. 64, 1913. 



14 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

however, susceptible to concentration, yielding a concentrate which 
may contain from 50 to 71 per cent of metal, depending upon the fine¬ 
ness to which the crude ore is ground and the strength of the magnets 
used in the process. (See page 69.) 

It has been learned that there are some large deposits of ore of this 
kind in the Piedmont area of North Carolina and in tlie mountain dis¬ 
trict of North Carolina and Tennessee. Those in the Piedmont area 
are not of immediate economic importance because they are too far 
from furnaces. Most of those in the mountain district are within an 
area that should be contributory to Johnson City, but at present some 
of them particularly those in Ashe County, N. C., are unavailable 
because too far from the railroad. The largest deposits in the 
entire district, so far as we know, are on a belt passing through Cran¬ 
berry in Avery County, N. C., and extending northwest into Carter 
Countv, Tenn. At Cranberry is the well-known Cranberry mine which 
has been furnishing ore to the blast-furnace at Johnson City for several 
decades. This is regarded as the type of all other non-titaniferous 
magnetites in the mountain district except one, at Lansing, Ashe County, 
which is in marble. The Cranberry vein is in a gneissoid granite. 

One of the principal objects of the study was to determine the 
origin of the Cranberry deposit so that some notion might be gained 
as to whether it extends beneath the present workings of the mine or 
is merely a superficial phenomenon. Since the ore was found to be 
closely associated with an epidotized pegmatite which was originally an 
augite syenite-pegmatite, it is believed to be deep-seated in origin and 
consequently may be expected to continue to depth with approximately 
the same character as in the developed portion of the vein. 

The ore occurs in the vein as a series of lenses connected with one 
another by thin strips of ore. If the vein, as appears probable, is as 
rich in ore beaneath the present bottom of the mine as above it, there is 
present in 1,800 feet of the vein and within a depth of 550 feet beneath 
the present lowest mine-level about 1,700,000 tons of ore of the same 
quality as that which has already been taken out. 

The Cranberry vein continues without interruption for 5^ miles 
northwest of Cranberry into Carter County, Tennessee, and in it are lenses 
of ore which have been opened at the Wilder, Teegarden, Peg Leg and 
other mines. A conservative estimate of the ore existing in the vein 
between the Cranberry and Peg Leg mines is 2,250,000 tons for every 
100 feet depth. (See pages 76 to 80.) It is not known how much of 
this ore might be mined and concentrated with profit, but it is probable 
that at a number of places the lenses are sufficiently large to warrant 
working, provided there were some provision made for their concen¬ 
tration at a point on the railroad within convenient reach of all the 
operations. Such a point is believed to be situated near Roan Moun- 


PREFACE AND SUMMARY 


15 


tain Station, to which the ore from any place on the vein might be trans¬ 
ported by a down-grade haul. 

So far as has been determined there are no other deposits within 
reasonable distance of Johnson City that are large enough to warrant 
the construction near them of concentrating plants. Nor are there 
any, except those on the Cranberry vein, that are near enough to Roan 
Mountain to deliver crude ore to a concentrating plant at that point 
at a cost that would yield a profit. There is an abundance of ore scat¬ 
tered through the mountains but it is in such small deposits as to be 
unavailable at the present price of ore. 

In Ashe County there are several deposits of fair size, but they are 
so far from railroads that they would be expensive to operate. The de¬ 
posits on New River contain at least 700,000 tons of merchantable ore 
and those near Lansing about 225,000 tons but the enormous tonnages 
that have been supposed to exist in this County have not been developed 
by exploration and are not suggested by surface indications. 

d. The only deposit of economic importance in the mountain dis¬ 
trict that is not in gneissic rocks is that of the Ashe Mining Company 
at Lansing, Ashe County, which is in marble. The deposit is small 
and its content of iron is small, but because the gangue is marble the 
ore finds a ready sale. The ore consists of grains of magnetite in a 
white marble that contains in addition to magnetite small amounts of 
phlogopite, aetinolite, and quartz. It is cut by veins of actinolite and 
dark hornblende and of a fine-grained aplitic rock, believed to correspond 
to the pegmatite at the Cranberry mine. The ore is thought to have 
an origin analogous to that of the Cranberry ore, i. e. to have been de¬ 
posited by ferruginous materials accompanying pegmatitic intrusions. 
Marble ores are believed to be rare in the mountain district because 
marbles are rare among the pre-Cambrian rocks of the district. 

e. Since the non-titaniferous magnetite deposits of the mountain 
district are found in the pre-Cambrian rocks of the district and are asso¬ 
ciated with pegmatites that are not known to penetrate the Cambrian 
rocks it is inferred that the ores are pre-Cambrian in age. 

The non-titaniferous magnetites of the Piedmont area are all asso¬ 
ciated with gabbros and other basic rocks that are believed to be pre- 
Cambrian, and consequently, these ores are also inferred to be of pre- 
Cambrian age. 

The titaniferous ores are thought to be genetically connected with 
peridotites of the same age as the peridotite rocks that are so common 
all along the east side of the Appalachian ranges. If these are pre- 
Cambrian the titaniferous ores are likewise pre-Cambrian. 

The age of the hematitic magnetites is not known, but if the rocks 
associated with them are Algonian, as probably is the case, these ores 
are also pre-Cambrian. 





































































































































































#> 




. 












The Magnetic Iron Ores of East Tennessee 
and Western North Carolina 

By W. S. Bayley. 


CHAPTER I. 

GENERAL CONSIDERATIONS 

The iron ores of East Tennessee and western North Carolina com^ 
prise magnetite, titaniferous magnetite (or mixtures of magnetite with 
ilmenite, or with rutile), brown hematite (limonite and goethite), and 
mixtures of magnetite with hematite or martite. Hematite also occurs 
but in such small quantities that it has never been mined. The brown 
hematite, magnetite and titaniferous magnetite have been mined and 
smelted, but in later years the titaniferous varieties have been completely 
neglected, because not adapted to modern blast-furnace practice. Until 
within a few years past the magnetite deposits furnished nearly all the 
ore, but recently the brown ores have become more and more important. 
Almost all of it came from North Carolina. Since 1900 the production 1 
has been: 


1922—Magnetite 

= 4,321 

tons; 

Brown 

ore=l 2,958 

tons. 

1921— 

6 6 

-- 

( 6 

6 6 

= 2,583 

6 6 

1920— 

i 6 

=44,482 

6 6 

6 6 

=27,328 

6 6 

1919— 

66 

=43,483 

66 

6 6 

=15,295 

66 

1918— 

66 

=60,593 

66 

6 6 

=47,739 

6 6 

1917— 

66 

=55,353 

6 6 

66 

=35,644 

66 

1916— 

66 

=60,043 

6 6 

66 

= 4,263 

66 

1915— 

66 

=65,596 

66 

6 6 

= 857 

6 6 

1914— 

66 

=57,667 

66 

6 6 

=. 

66 

1913— 

66 

=69,235 

6 6 

6 6 

= 

66 

1912— 

6 6 

=68,322 

6 6 

6 6 

=. 

66 

1911— 

6 6 

=84,782 

66 

6 6 

= 

66 

1910— 

6 6 

=65,278 

6 6 

6 6 

= 

66 

1909— 

6 6 

=61,150 

6 6 

6 6 

=. 

66 

1908— 

66 

=48,522 

6 6 

6 6 

- . 

66 

1907— 

66 

=75,638 

66 

66 

=. 

66 

1906— 

66 

=56,057 

66 

6 6 

= 

6 6 

1905— 

6 6 

=56,282 

66 

66 

=. 

66 

1904— 

66 

=64,347 

66 

6 6 

=Some 


1903— 

6 6 

=82,851 

66 

66 

=Some 


1902— 

6 6 

=34,336 

6 6 

66 

= 3,500 tons. 

1901 — 

66 

= 2,020 

66 

6 6 

= Little 


1900— 

6 6 

=20,479 

66 

66 

= Little 



iTaken from the reports of the North Carolina Geol. and Econ. Survey and Min. Re¬ 
sources of the U. S. 
















18 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Most of the brown ore produced since 1915 came from Madison 
and Cherokee counties in North Carolina, the greater portion from 
Cherokee County. In the earlier years of the century it was obtained 
mainly from Chatham and Johnston counties for the use of the furnace 
at Greensboro which was closed about 15 years ago. The magnetite 
came mainly from Cranberry in Avery County. A small quantity has 
been contributed by deposits at other localities from time to time, but 
this was obtained principally in the development of explorations and 
consequently was only an incident. Most of it was from deposits in 
Carter County, Tenn., where search was made for the western extension 
of the Cranberry vein. 

In this report attention is directed mainly to the magnetites and 
magnetite-hematite ores of Carter County, Tenn., and to the magnetite 
ores of Ashe and Avery counties and the titaniferous magnetite of Guil¬ 
ford County, N. C. (See index map, Figure 1.) A few deposits in other 
portions of North Carolina are described only briefly, since at present 
they are of little importance. The deposits of Avery and Ashe counties, 
N. C., and Carter County, Tenn., are believed to offer more promising 
opportunities for successful development than those elsewhere, and 
therefore the time available for the field work was devoted almost ex¬ 
clusively to them. Information concerning deposits in other portions 
of North Carolina is gathered mainly from the literature. 

The magnetic ores usually occur in areas of granites, gneisses and 
schists, but in Ashe County, N. C., a deposit of magnetite occurs in 
marble. In all, or nearly all cases, the magnetic ores are associated 
with pegmatites or aplites or with the alteration products of basic in- 
trusives. 

MAGNETITES AND TITANIFEROUS MAGNETITES 

COMPOSITION AND CLASSIFICATION 

The magnetic ores have already been referred to as comprising 
three types, one of which consists essentially of magnetite, another of a 
mixture of magnetite and a titanium-bearing mineral, and the third of 
a mixture of magnetite and hematite. The ores of the first type are 
usually spoken of as magnetite and those of the second type as titanifer¬ 
ous magnetite or titaniferous iron ore. The titaniferous and non- 
titaniferous magnetites differ not only in the presence or absence of 
considerable quantities of titanium but also in the presence or absence 
of chromium. Both types are comparatively free from phosphorus and 
sulphur. 

The difference in the two types is indicated by the following series 
of analyses, most of which were taken from the preliminary report of 


MAGNETITES AND TITANIFEEOLo MAGNETITES 


19 


H. B. C. Nitze 2 on the iron ores of North Carolina, published in 1893. 
The first 9 and the last 1 are of the non-titaniferous types. Most of 
them contain a little titanium but it is in such small quantities as to be 
negligible. The other 7 represent the titaniferons varieties. Most of 
the specimens analyzed were from deposits in Ashe County, but they 
are representative of the magnetic ores throughout the crystalline areas 
of both N orth Carolina and Tennessee. 


Selected Analyses of North Carolina magnetic ores 



SiO* 

Fe 

S 

P 

P ratio 

TiCh 

Mn 

Cr203 

1 

14.28 

57.21 

tr 

.060 

.105 

. 12 

• .16 

none 

2 

5.27 

64.64 

.115 

.004 

.006 

. 95 

. 19 


3 

19.83 

51.55 

. 137 

.042 

.081 

.207 



4 

32.06 

37.14 

.071 

.004 

.010 

. 106 



5 

32.59 

36.41 

.200 

. 003 

.008 

. 118 



6 

28.60 

37.30 

.090 

. 014 

.038 

.082 



7 

20.36 

45.06 

. 130 

Oil 

.024 

.040 



8 

3.20 

65.40 


Oil 

.016 

.000 

2.58 


9 

6.85 

63.55 

tr 

. 009 

.014 

.060 



10 

1.80 

54.17 




14.46 

.96 

.97 

11 

4.71 

48.41 

.089 

. 023 

. 048 

13.74 

.11 

.34 

12 

1.31 

55.06 

tr 

tr 

tr 

13.60 

.70 

.72 

13 

5.73 

52.22 

tr 

tr 

tr 

12.96 

.26 

.390 

14 

9.90 

46.81 

. 137 

. 025 

.053 

6.03 


. 630 

15 

6.35 

57.66 

.061 

.008 

.013 

4.69 


.505 

16 

4.75 

52.23 

. 112 

.021 

.040 

8.91 


1.190 

17 

17.25 

48.87 

.057 

.066 

. 135 

.210 


. 000 


1. Cranberry mine, Avery Co., N. C. Analyst: J. G. Fairchild, U. S. Geol. Surv. 

2. Cranberry mine, 10th Census Report, vol. 15, p. 326, 1886. 

3. Long Trench, Red Hill, Poison Branch belt. Nitze, North Carolina Geol. Surv., 
Bull. No. 1, p. 143, 1893. 

4. Opening No. 2, Red Hill, Poison Branch belt. Idem. p. 144. 

5. Opening No. 3, N. W. side. Red Eill, Poiscn Branch belt. Idem. p. 144. 

6. Opening S. side of road, Poiscn Branch mine, Pciscn Branch belt. Idem. p. 150. 

7. Lower portion of opening, N. side cf road, Poison Branch mine, Poison Branch 
belt. Ide n. p. 150. 

8. Piney Creek opening. Poison Branch belt. Idem. p. 153. 

9. Jos. Graybeal, main opemng, Poison Branch belt. Idem. p. 155. 

10. Shaw mine, Rockingham Co., Kerr and Hanna, Geol. of North Carolina, vol. 2, 
chap. 2, p. 150, 1888. 

11. Dannemora mine, Rockingham Co., 10th Census Report, vol. 15, p. 311, 1886. 

12. Sergeant shaft, Tuscarora mine, Guilford Co., Kerr and Hanna, Op. cit., p. 149. 

13. Wm. Young, Titaniferous belt, or Helton Creek belt. (See page 215.) 

14. McCarter opening, No. 4, north of road, Titaniferous belt. Nitze, Bull. No. 1, 
North Carolina Geol. Surv., Bull. No. 1, p. 157, 1893. 

15. Bauguess Place, Titaniferous belt. Idem. p. 160. 

16. Pennington’s Place, Titaniferous belt. Idem. p. 160. 

17. Kirby Place, Titaniferous belt. Idem. p. 160. 

The most striking features of these analyses are the marked dif¬ 
ferences in the quantity of titanium dioxide (Ti0 2 ) in numbers 10 to 
16 as compared with the quantity shown in numbers 1 to 9 and in num¬ 
ber 17. Aside from this, the difference is the more noticeable with 
respect to chromic oxide (Cr,0 3 ). All the titaniferous ores contain 
this oxide, whereas none has been found in those in which titanium is 
present in less than 1 per cent of Ti0 2 . Moreover, there is another 


2 Nitze, H. B. C., Iron Ores of North Carolina: North Carolina Geol. Surv., Bull 
No. 1, Raleigh, 1893. 





20 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


distinction which is not evident from inspection of the analyses. The 
magnetites frequently contain comparatively large quantities of man¬ 
ganese whereas in the titaniferous ores this element is in small quantities 
only. Phosphorus is below the Bessemer limit in both kinds of ore 
except in a very few cases, in which it is slightly above the limit. Sul¬ 
phur is always in small quantities. The titaniferous ores are not avail¬ 
able for blast-furnace use only because of their high content of titanium. 



10 0 to 20 30 MILES 

i—i■ ■ ■ ■ ‘ ■ 


Figure 1. Index map of East Tennessee and Western North Carolina, showing 
positions of detail maps. 


OCCURRENCE 

The magnetites and the titaniferous iron ores are alike in general 
appearance and in their occurrence as lenses and veins in gneisses, 
schists and other crystalline rocks. Those in the mountain district are 
associated with Archean country rocks. The country rocks associated 
with the deposits in the Piedmont area are quartzites, marbles, micaceous 
schist, and slates that may be of Cambrian age, and gneisses and old 



































MAGNETITES AND TITANIFEROUS MAGNETITES 


21 


volcanic lavas and tuffs which are younger than Archean, but probably 
older than Cambrian. 3 

Nitze 4 in his discussion of the magnet itic ores described them as 
occurring in belts, inferring that they are distributed along continuous 
lines. This inference may be correct in a broad way, i. e., the deposits 
are usually in zones parallel to the general structure of the region, but 
in a narrower sense they are in short discontinuous lines or series of 
parallel lines that may be close together in some places and widely apart 
in others. In Ashe County, for instance, Nitze designates several belts 
of non-titaniferous magnetites and one belt of titaniferous varieties. 
In the titaniferous belt, because of its position, he is compelled to place 
the Kirby mine, which, however, contains only a trace of titanium and 
no chromium. Moreover the Kirby ore is associated with rocks that 
are different from those associated with the titaniferous magnetites in 
the same belt, and are like those associated with the ore at Cranberry, 
which, as is well-known, is also non-titaniferous. In Avery County he 
designates as a belt of titaniferous ores a series of deposits of different 
kinds, which are so distributed that a line joining them crosses the 
structure of the country. 

In some places the deposits are actually in line with one another, 
where they are situated along a zone of weakness in the country rock, 
usually a zone along which the schistosity is more pronounced than else¬ 
where. In other places they are in schistose zones but not in the same 
plane. In these places the zone itself consists of a series of planes along 
which marked schistosity has taken place, but the loci of maximum weak¬ 
ness are not always in the same plane. In these zones the deposits may be 
within the limits of a comparatively narrow belt crossing the country, 
but not along the same line within the belt. Their long axes may have 
the same direction, but the projections of their strikes do not pass 
through one another, but are parallel. In still other places, so far as 
now known, the deposits are isolated. 

In some instances the zones within which the deposits are distri¬ 
buted may cross the country for many miles; in other instances, they 
are short. But even in the case of the long zones the lines passing through 
deposits on the same strike are short, and often deposits that at first 
sight are thought to be on the same line are discovered when observed 
carefully to be on parallel lines. 

UCeith, Arthur, and Sterrett, Douglas B., The resources of the Kings Mountain dis¬ 
trict, North Carolina and South Carolina, U. S. Gecl. Surv., Bull. 660, p. 126, 1918. 

<Nitze, H. B. C., Iron ores of North Carolina, N. C. Geol. Surv., Bull. No. 1, p. 230, 
Raleigh, 1893. 



MAGNETIC IRON ORES uF EAST TENN. AND WESTERN N. C. 


OO 


HEMATITIC MAGNETITES 

The ores that are mixtures of magnetite and hematite are limited 
to a small area in Carter County, Tennessee, where they occur as layers 
between gneisses and chloritic schists, on the mountains near Elk Mills. 
Fairly large explorations have been made at one or two points, but the 
quantity of ore developed by them is not large, nor so far as is known 
has any of it been shipped. The distance to the nearest railroad is 
about 6 miles over hilly roads, so that at present the ore is not avail¬ 
able for use in the blast-furnace at Johnson City, Tenn. 

The most promising ore of this type is an extremely fine grained, 
obscurely layered and slightly schistose specular ore that resembles in 
appearance some of the more massive specular ores of the Marquette 
district. Others are flinty hematities. 

Analyses of two specimens show that they are low in phosphorus 
and free from titanium, and that their iron is present in widely varying 
proportions of hematite and magnetite. 

Partial analyses of hematitic magnetite ore, Carter County, Tennessee 



Teagarden mine 

Keystone 

Silica (Si 0 2 ). 

21.94 

14.86 

Alumina (APO3). 

1.26 


Ferric iron (Fe> 0 3 ). 

54.76 

82.84 

Ferrous iron (FeO). 

21.52 

1.40 

Phosphorus pentoxide (P2O5). . . 

.026 


Other constituents. 

.53 



100.036 99.10 

The first analysis indicates a mixture of about 6.5 per cent of hema¬ 
tite and 70 per cent of magnetite, and the second a mixture of 79.8 per 
cent of hematite and 4.4 per cent of magnetite. 












CHAPTER II. 

HISTORICAL REVIEW OF LITERATURE 


Before 1827 iron ores had been worked in Lincoln county, N. C., 
presumably for local forges, for in the first geological report of the first 
State Geologist * 5 of North Carolina we read, 

Compared with the other regions of the globe, the eastern section of the conti¬ 
nent of North America is, with a single exception, not rich in the metallic ores. With 
the most important and valuable of all, the ores of iron it abounds. ... So far as we 
can judge from observations hitherto made, the mines of iron and coal, with the lead 
mines of the Missouri, are to constitute the principal mineral wealth of the United 

States.as the county of Lincoln was the first to embark in the iron 

manufacture, so it is probable that she will maintain the standing she has acquired. 
The superior excellence of the ores from which the metal is extracted . . warrants this 
conclusion. Nor is the demand just at present, greater than this single county might 
supply, because of the high cost of labor in America and the very trifling expense of 
transporting such an article as iron across the Atlantic.” 

Dr. Gerard Troost, State Geologist of Tennessee in 1837 in his 
fourth report, speaks of the Cranberry ore deposit as follows: 

“The iron ore of the primordial formation is generally that kind which is called 
magnetic iron ore. Immense quantities of this ore are found in the northeastern parts 
of the t nited States. And not to speak of the vast deposits of this ore in similar for¬ 
mations in Washington County, Missouri, which have formed these fifty years one of 
the wonders of the west, nor those of Elba, which produced most of the iron used by 
the Romans, and the mines of which are yet considered as inexhaustible; I must men¬ 
tion one situated near the limit which separates the State of Tennessee from North 
Carolina, at the foot of the Roan Mountain, in Carter county. It seems to be an ex¬ 
tensive vein of rich magnetic iron ore, similar to that of some parts of Sweden, and is 
accompanied with the same minerals as the Swedish ore, namely, a variety of pyroxene 
(salite or malacolite).” 

Again in 1854 the existence of iron ores in parts of North Carolina 
was referred to by Whitney 6 , but the ores were not discussed. Pie 
stated that iron ores could be found in the metamorphic rocks in the 
western part of the State, but declared that they were too remote to 
be of much consequence to the iron manufacturer. They were con¬ 
sidered of importance only locally, as the Census of 1850 had reported 
but 400 tons of the metal produced in the entire State. 

A few years later, however, Emmons 7 began to emphasize the value 
of the ores and recommended the construction of a national foundry at 
Deep River. The Deep River deposits are titaniferous magnetites that 

i Mitchell, Elisha, Report on the geology of North Carolina, part III., pp. 25-26, No¬ 

vember, 1827. 

6 Whitney, J. D., Metallic wealth of the United States, p. 474, Philadelphia, 1854. 

'Emmons, E., Geol. report of the midland counties of North Carolina, pp. 112-128, 
Raleigh, 1856. 

National Foundry.—Deep River, N. C. Raleigh, 1859. Also Min. Mag. ser. 1, 
vol. 10, pp. 281-288, 1858. 

A national foundry in North Carolina; De Bow’s Review, vol. 24, pp. 403-409, 1858. 



24 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

are of no economic importance at the present time, so that it is unneces¬ 
sary to refer to them further in this place. They will be discussed later 
in connection with the character and origin of the titaniferous ores. 

Emmons recognized 3 belts of ore in the midland counties, of which 
the western one passes 6 or 7 miles east of Lincolnton and extends to 
King’s Mountain in Gaston County. The ore was described as being 
in talcose slate between quartzite and gneiss belts. It was declared to 
be in flat lenses which lie obliquely in the slate, one lens succeeding 
another along the strike in such a manner that each “laps on to the west 
side of another flattened oval mass, which lies behind the first.” The 
deposits in Lincoln County were reported to have been worked for a 
long time for local forges. All the ore was believed to be in veins of 
igneous origin in the sediments which were regarded as the oldest in 
the State. The author surmised that not all the deposits had been 
found but he thought there were no inducements for further search 
since the ore already known “is in sufficient quantity to serve all uses.” 

The other two belts are east of the Lincoln County belt, outside of 
the area discussed in this bulletin. 

In the Iron Manufacturer’s Guide 8 , published 3 years later, Lesley 
mentions the existence of the same 3 belts of ore in the State, of which 
the one that passes east of Lincolnton is described in some detail. He 
states his view as to the sequence of the beds associated with the ores 
and declares them to be Taconic. He indirectly refers to the ores of 
Cherokee County and elsewhere, since he states that bloomeries supplied 
by these ores had been working with them for many years. 

During the next ten years several 9 other references to the iron ores 
of the State were made in published articles, but none of them con¬ 
tributed any new information as to their quality or abundance. 

The first systematic account of the North Carolina ores was given 
by Kerr 10 , who discussed the ore deposits by districts, describing them 
in considerable detail, illustrating his descriptions by many figures 
and maps, and quoting many analyses. Many of the mines described 
are, however, east of the areas discussed in this report and these, there¬ 
fore, need not be referred to here. 

The ore in the belt passing through Catawba, Lincoln and Gaston 
counties was reported to consist of talcose, chloritic, quartzitic or actin- 
olitic schists impregnated with granular magnetite and hematite, and 
lying near a quartzite, which Emmons had declared to be a marker for 

8 Lesley, J. Peter, Iron Manufacturer’s Guide, pp. 449, 451-452, N. Y., 1859. 

“Sergeant, J. D.,The titaniferous iron mines of North Carolina: Eng. and Min. Jour., 
vol. 11, p. 130, 1871. 

Colton, H. E., Mines i,n North Carolina: Eng. and Min. Jour., vol. 11., p. 323, 1871. 

Genth, F. A., Mineral resources of North Carolina: Jour. Frank. Inst., vol. 62, Dec. 

1871. 

Lesley, J. P., Note on the titaniferous iron belt near Greensboro, N. C.: Am. Philos. 
Soc. Proc., vol. 12, pp. 139-158, 1873. 

10 Kerr, W. C., Report of the Geol. Survey of North Carolina, vol. 1. Physical geog¬ 
raphy, resume, Econ. Geol., pp. 217-271, Raleigh, 1875. 



HISTORICAL REVIEW OF LITERATURE 



the ore deposits. The belt contains, according to Kerr, two parallel 
“beds,” the westerly being the more productive, with 12 feet to 20 feet 
of talcose or chloritic slates between them. 

The belt is said to divide itself into two groups of beds, the northern 
in Lincoln county, and the southern in Gaston county. The principal 
deposits in both groups were described in some detail, and attention was 
called to the great size of some of them. 

That portion of the belt in Gaston County was stated to be similar 
to the portion in Lincoln County, but the ore contains a little more 
hematite and usually has a red streak. The belt is double, as it is fur¬ 
ther north, but the two parts are much farther separated. 

Other deposits of magnetite were mentioned as existing in Lincoln 
and Gaston counties, but as most of them are not in the belts recognized 
by the author they were simply referred to. 

The Cranberry ore-bank, however, was briefly described. The 
country rocks around the deposit were stated to be hornblende slate 
and syenite, and gray gneisses and gneissoid slates. At that time 
the mine had not been opened, the ore being taken from the loose masses 
scattered through the soil over the vein. Prof. Chandler is quoted as 
stating that it was the best iron ore he had ever analysed. In regard to 
quantity Kerr believed it “exceeds the great deposits of Missouri and 
Michigan and at least equals anything in the Champlain region (page 
266.)“ He gave no details about the vein, merely declaring that “the 
epidote is not entirely confined to a single stratum, or part of the bed, 
being mixed to some extent with the pyroxenic rocky gangue which 
most abounds toward the western side of the vein.” (Page 266.) 

Other ore beds like those at Cranberry were reported to exist to 
the northwest, west, southwest, and southeast of the Cranberry bed, 
many of them like the Cranberry deposit; but most of them were known 
only by their outcrops and no definite information as to their size was 
available. 

Important magnetite deposits were said to occur, also, in Ashe 
County—the best known being on Horse Creek, at Hampton’s and at 
Gray bill's, and the largest on Helton Creek. The veins were stated to 
be in gneiss and syenite and their gangue to be pyroxene and epidote. 
From the Helton Creek deposit, according to the author, a coarse¬ 
grained, pure magnetite had been taken during a long period. One 
vein is 9 feet wide and another 18 feet wide. Other deposits occur in 
the district but they are known only by hand specimens. 

The titaniferous ores of Guilford County were described in great 
detail, much of the description being taken from a report made by Dr. 
J. P. Lesley for the North Carolina Centre Iron and Mining Company. 
In this report Lesley refers to the origin of the ores and reaches a con- 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


26 


elusion which is opposed to that of Emmons, who regarded them as 
igneous veins. (See page 24.) Lesley declares (page 241) that: 

“The beds were deposited like the rest of the rocks in water;, de¬ 
posited in the same age with the rocks which hold them; are in fact 
rock-deposits highly charged with iron; and they differ from the rest 
of the rocks only this respect: that they are more highly charged with 
iron. In fact all our primary (magnetic and other) iron ore beds obey 
this law. They are merely certain strata consisting more or less com¬ 
pletely of peroxide of iron, with more or less intermixture of sand and 
mud, which when crystalized, fall into the shape of feldspar, hornblende, 
mica, quartz, &c., &c.“ 

The author states that magnetite and titaniferous iron ores were 
known to occur also in Madison County, but they were not examined. 

Within the next few years S. T. Abert 11 in a report to the Chief 
of Engineers, U. S. Army, made mention of the existence of iron ores in 
Gaston, Lincoln and Catawba counties and a writer who signed himself N 12 
called attention to the construction of a railroad from Johnson City, 
Tenn., to Cranberry in order to tap the ore at Cranberry for the use of 
furnaces in Tennessee. He estimated that not more than 50,000 tons 
had been taken from all the lenses in the vicinity of the village, and 
advised further exploration. He also noted the presence of other de¬ 
posits southwest of Cranberry and of a titaniferous ore on Rocky Creek. 

In 1883 and 1884 Smock 13 again mentioned the existenceof magne¬ 
tite in western North Carolina, and in the earlier year the Handbook 14 
of the State of North Carolina contained a summary of the State’s iron 
resources. Most of the statements in these articles are repetitions of 
those published in Kerr's report. 

In the Mineral Resources of the L T nited States for the following 
year, however, J. M. Swank 15 made precise mention of the ore-bank at 
Cranberry, which he declared had been worked for 100 years to supply 
bloomeries in the neighborhood. At the time he wrote preparations 
were being made to ship the ore to distant points and to smelt it in a 
small charcoal furnace that had been built at the mines. The ore was 
said to possess “superior adaptability to the manufacture of steel.” 
Several analyses appear in the report, but they are useful at the present 
time only in showing that the character of the ore produced has remained 
uniform for 40 years. 

u Abert, S. T., Examination of Catawba River from South Carolina line to Old Fort, 
North Carolina. U. S. Army, Chief of Engineers, Report for 1876, pt. 1, pp. 367-376, An- 
pendi'x G, 1876. 

12 N., Magnetic iron ores of the Unaka Mountains, North Carolina and Tennessee- 
Eng. and Min. Jour., vol. 25, pp. 272-273, 293-294, 1878. 

13 Smock, J. C., U. S. Geol. Surv., Min. Resources for 1882, p. 715, 1883. 

Smock, J. C., Geologico-geographical distribution of the iron ores of the Eastern U. S : 
Am. Inst. Min. Eng. Trans., vol. 12, pp. 130-144, 1884; and Eng. and Min. Jour., vol. 37 
pp. 217-218. 230-232, 1884. 

l4 Handbook of the State of North Carolina, exhibiting its resources and industries. 
Prepared under the direction of the Board of Agriculture, Raleigh, 1883. 

l5 U. S. Geol. Surv., Min. Resources, 1883-1884, pp. 277-278, 1885. 




HISTORICAL REVIEW OF LITERATURE 


27 


A series of analyses are also appended to an article by Porter 16 
on the iron ores and coals of Alabama, Georgia and Tennessee, and 
some of them are of samples of magnetites collected in North Carolina, 
among them samples of Cranberry ore and of a titaniferous ore from 
Roan Mountain. Unfortunately there are no precise locations for most 
of the samples. While Porter regarded the Cranberry occurrence to 
be “a great bed” he believed that there are equally large ones in Ashe 
County and perhaps elsewhere. 

Two years later Swank 17 again referred to the “celebrated Cranberry 
ore” as being well adapted to the manufacture of steel by the acid pro¬ 
cess, and stated that similar ores occur elsewhere in the western part of 
the State, and John Birkinbine 18 referred briefly to the Cranberry de¬ 
posit and to various veins of magnetite elsewhere and quoted analyses 
by Britton and McCreath of the Cranberry ore and of an average of 23 
samples of limonites from the southwestern part of the State. 

About this same time appeared the Census Report 19 on the Mining 
Industries of the United States during the Census Year beginning July 
1, 1886. In this report brief descriptions of all the mines in North 
Carolina and analyses of their ores are given. This report will be re¬ 
ferred to repeatedly in the present discussion, partly because it gives us 
the earliest details we have of the mines and partly because it contains 
the most complete analyses of the ores that had been published at that 
time. As it was written when the magnetites were being explored most 
vigorously it contains much information which would have been lost 
if not preserved in its pages, because many of the deposits then exposed 
to sight have since been covered by debris and are no longer available 
for study. 

A few references were made to the ores during the next two years 
but they added very little to the information given us by Kerr and Willis. 

During the course of a trip across the State, Britton 20 visited the 
Cranberry mine, which he reported to be in rocks that are probably of 
the same age as those in which the New Jersey ores are found. The ore 
is described as being in a bed at least 100 feet thick, and as being self- 
fluxing, probably in consequence of the presence in it of much dark- 
colored pyroxene. With it is associated some epidote and insignificant 
amounts of white quartz and calcite, and bands of feldspathic rock. 
The strata are said to be much contorted. 

In the following year were published the notes of a lecture delivered 
by John Birkinbine 21 on the iron ore resources of the country in which 

16 Porter, J. B., The iron ores and coals of Alabama, Georgia and Tennessee. Iron ores 
of North Carolina: Am. Inst. Min. Eng. Trans ,,vol. 15. pp. 190-191, 206, 1886. 

17 U. S. Geol. Surv., Min. Resources, 1886, p. 36, 1887. 

18 Idem.,pp. 82-83. 

19 Willis, Bailey, Notes on samples of iron ore collected in North Carolina: 10th Census 
U. S., vol. 15, pp. 301-329, 1886. 

20 Britton, N. L., Geol. notes in Western Virginia, North Carolina and Eastern Ten¬ 
nessee: N. Y. Acad. Sci. Trans., vol. 5, pp. 215-223, 1887. 




28 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

he referred to the existence of magnetites in North Carolina and the 
fact that the first discovery of iron ores in what is now the United States 
was made in this State in 1885. 

The first fairly complete account of the State’s iron ores is to be 
found in the report of Kerr and Hanna 22 , published in 1888. In this 
volume of 350 pages, 64 are devoted to the iron ores. The deposits are 
discussed by districts as in the first report (see page 24), and each mine 
that was open at the time the field work was done is described in detail; 
and in the cases of all important mines the descriptions are illustrated 
by maps. The character of the ore in each mine is also carefully de¬ 
scribed with the aid of many illustrations and numerous analyses. 

The general discussion of the deposits is identical with that in the 
earlier report except that Hanna is inclined to think that the ore was not 
deposited with the original sediments (compare page 26), but was 
later formed by some metamorphic process. The greatest advance 
over the earlier report is in the discussion of the individual mines. Each 
of these is described by name and the manner of occurrence of the ore 
in many of them is illustrated by figures, some of which are reproduced 
in the pages following. Many of the descriptions are also quoted in 
part, so that they will not be referred to at greater length in this place. 
Numerous analyses enrich the descriptions and render them all the more 
valuable, since they were in many cases made on fresher samples than 
it is possible to secure at present. Many of them, however, are reprinted 
from Kerr’s earlier report. 

Brief reference is made to large deposits of magnetite in Ashe 
County, but no detailed description of them is given. 

No other descriptions of the ores of North Carolina are met with 
until the publication of Nitze’s report in 1893, but references to them 
are found in several articles. Whitfield 23 gave a partial analysis of the 
Cranberry ore. T. S. Hunt 24 referred to the ores of North Carolina 
in his general description of the iron ores of the United States, and J. 
M. Swank 25 in his “History of the Manufacture of Iron in All Ages,” 
but both of these writers merely mentioned the Cranberry and some 
other deposits. Hunt regarded the Cranberry ores and other magne¬ 
tites in the extreme western part of the State as belonging in his Lau- 
rentian series, and believed that the ores and the gneisses with which 
they are associated were deposited from a great ocean. 


21 Birkinbine, John, The iron ores of the United States: Jour. Franklin Inst., vol. 126, 
Phila., pp. 196, 198, 1888. 

22 Kerr, W. C., and Hanna, G. B., Ores of North Carolina: Geol. of North Carolina- 
vol. 2, chap. 2, pp. 125-187, Raleigh, 1888. 

23 Whitfield, J. E., U. S. Geol. Surv., Bull. 60, p. 168,1890. 

24 Am. Inst. Min. Eng. Trans., vol. 19, pp. 3-17, 1890, and Eng. and Min. Jour., vol. 50. 
pp. 600-601, 622-621, 1890. 

25 Swank, J. M., Phila. Am. Iron & Steel Assoc., pp. 272-275, 1892. 



HISTORICAL REVIEW OF LITERATURE 


£9 


In 1892 H. B. C. Nitze 26 gave a preliminary account of his work 
on the iron ores of Ashe County in which he described the main deposits 
and quoted a few analyses. In the following year he 27 published an 
advance summary of a study of all the iron ores in the State, and in the 
same year appeared his full report. 28 

In Nitze’s report is given a description of all the iron ore mines and 
all the undeveloped iron ore deposits within the State. At the time the 
report was being written access was possible to many deposits that have 
since been covered so that its pages must furnish us much information 
that is not elsewhere obtainable. There is very little in the report that 
was not covered in the reports of Kerr and Hanna and of Bailey Willis, 
except with reference to the development of the mines, and the compo¬ 
sition of the ores. Many new analyses are published and there are 
given a few geological notes. For the first time the Cherokee County 
limonites and the Ashe County magnetites are described in detail and 
their geology outlined. An attempt is made to show that the ores in 
the crystalline rocks occur in belts that are apparently regarded as re¬ 
presenting definite horizons. In Ashe County, for instance, the mag¬ 
netites are grouped in (1) the Ballou, or River, belt, (2) the Red Hill, 
or Poison Branch belt, and (3) the Titaniferous belt. There is no 
general discussion of the origin of the ores, but here and there occur 
remarks as to the possible origin of individual deposits; but these, as a 
rule, are taken from Willis's article in the report of the Tenth Census. 
Repeated reference will be made to Nitze’s bulletin in the succeeding 
pages. 

Nothing of importance was contributed to the subject under dis¬ 
cussion between 1893 and the appearance, between 1903 and 1907, of 
Keith’s series of folios on the quadrangles in western North Carolina 
and neighboring portions of Tennessee and Kentucky. References had 
been made to the iron ores of North Carolina by various writers, but 
these references were merely interpretations of statements in Nitze's 
bulletin. Phillips 29 in an article in which he briefly discusses the mag¬ 
netic concentration of North Carolina magnetites questions the prac¬ 
ticability of concentrating them with profit and states that he doubts 
the value of any of the ores except those in the extreme western part 
of the State. 

In the volume “North Carolina and its Resources” 30 a brief account 
of the iron ore resources is given, but the material was taken almost 
without modification, except condensation, from Nitze’s bulletin. 


2«Nitze. H. B. C., The magnetic iron ores of Ashe Co., N. C.: Am. Inst. Min. Eng. 

Trans vol. 21, pp. 260-280, 1892. . 

27N C Geol Surv., First Biennial Report. 1891-1892, Raleigh, pp. 25-26, 1893. 
28Nitze, H. B. C., Iron ores of North Carolina: N. C. Geol. Surv., Bull. No. 1, pp. 239, 

Raleigln ^lso^ w B North Carolina iron ores and magnetic concentration: Eng. and 
Min ‘ 30 °vorth°Caroiina anti its resources: State Board of Agriculture, Winston, pp. 87-98, 


1896. 





30 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

The serious study of the details of the geology of the magnetite 
ores began with the appearance of the Federal geologists on the scene, 
when they undertook to map the cpiadrangles in which the ore bodies 
occur. 

Keith , as the result of his work in mapping several of the quadrangles 
in the western part of the State, obtained a general knowledge of the 
many magnetite deposits occurring in the crystalline rocks and inci¬ 
dentally developed the first precise views that have been published 
with reference to the origin of the great deposit at Cranberry. These 
views he gave briefly in the text of the Cranberry folio 31 , and agiin in a 
special article in a bulletin 32 of the Federal Survey. He described the 
Cranberry deposit as being one of a series reaching from near Old Fields 
on the North Toe River, northwestward, through Cranberry to Shell 
Creek in Tennessee. The line of outcrops lies in the Cranberry granite, 
and extends in a direction which is nearly parallel to the boundary of 
the granite with the older Roan gneiss. The ore is said to occur “as a 
series of lenticular bodies of magnetite in a gangue of hornblende, pyrox¬ 
ene, epidote, with a little feldspar and quartz, and a few unimportant 
minerals. The ore and gangue occur as a series of great lenses dipping 
toward the southwest at angles of 45°—50° about parallel to the planes 
of schistosity in the gneiss (schistose Cranberry granite). The ore is 
found in the gangue in the shape of smaller lenses, dipping southwest 
from 40° to 60°.“ They vary from a few inches to 50 feet in thickness 
and are from 2 to 5 times as long. Sometimes the lenses have sharp 
limits, but usually the ore and gangue grade into one another. More¬ 
over ore is sprinkled through the gangue and more or less gangue is 
scattered through the ore. 

The minerals composing the ore and gangue were thought to have 
been deposited long after the enclosing granite had solidified and indeed 
later than the deformation that produced its schistosity, since, as he 
supposed, they “are only slightly crushed or rearranged, although they 
are the same varieties which, in adjacent formations, show the greatest 
metamorphism.“ The ore deposit therefore was believed to be secon¬ 
dary. “It may have replaced a pre-existing mass of rock by solution 
and substitution of new minerals, or it may have been deposited from 
solution in open spaces in the inclosing formation.” The latter result 
was regarded as unlikely because of the great size of the deposit. It 
appeared more probable that the ore replaced an igneous, diabase-like 
mass that intruded the granite. Because diabases elsewhere in the 
region, though much altered by metamorphosing processes, have not 
produced ores, the author thought that water charged with mineralizing 
agents “dissolved and perhaps added to the rock minerals and rede- 

31 Keith, Arthur, U. S. Geol. Surv. Geol. Atlas, Cranberry folio (No. 90), p. 8, 1903 

32 Keith, Arthur, Iron ore deposits of the Cranberry district, North Carolina-Tennes- 
see: U. S. Geol. Surv., Bull. 213, pp. 243, 246, 1903. 




HISTORICAL REVIEW OF LITERATURE 


31 


posited them in favorable places, either in the old or in new chemical 
combinations.” The places of deposits were plainly controlled by the 
schistosity of the granite. In the granite are small veins and stringers 
of magnetite that may represent deposition from the mineralizing solu¬ 
tions where there was no readily alterable rock, and at other places the 
gangue minerals and even magnetite are developed in the mass of the 
red granite along more or less mashed zones. “These perhaps represent 
the places where alteration was most active; that is to say, the actual 
channels through which the mineralizing solutions passed.” 

Since the magnetite deposits were believed to be younger than the 
folding movements in the district and the Bakersville gabbro also 
younger than these movements, and since the magnetite bodies swing 
around the circumference of areas believed to be underlain by the gabbro 
in the granite and in the Roan gneiss west and southwest of Cranbery 
the author was led to suggest that “the magnetites are due to alterations 
begun by the gabbro intrusions.” However, since there are no gabbro 
intrusions in Ashe County the magnetites in the Ashe County area can¬ 
not have been produced by this process. The author thought the iron 
in this area may have been dissolved from the Roan gneiss through which 
mineralizing solutions must have passed in more than one epoch. 

There is a band of titaniferous magnetite deposits south of the 
Cranberry belt of non-titaniferous magnetite and parallel with it. “In 
as much as the two belts are in close proximity and each is extensive 
without overlapping the other, their depositing solutions were probably 
active at different times. Still another period of mineralization left 
its record in the pegmatite veins and lenses so common in this region. 
These, however, were crushed and distorted during the folding of the 
strata, and thus are so much older than the magnetite deposits that 
they can have no origin in common.” 

In the Asheville folio 33 the author calls attention to the presence 
of veins of magnetite in granite, mica gneiss, hornblende gneiss, and 
hornblende-mica gneiss, and states that in most places the ore is asso¬ 
ciated with a gangue of hornblende, epidote and quartz, as at Cranberry. 
It is worthy of notice that the magnetite deposits are not limited to 
the granite areas, as was intimated to be the case in the text of the 
Cranberry folio. 

The magnetites in the Mount Mitchell 34 quadrangle are nearly 
all titaniferous, but the author does not presume to offer any suggestions 
as to their origin. 

Two years later, in 1907, the three folios on the Nantahala, Pisgah 
and Roan Mountain quadrangles appeared. In these Keith 35 makes 

33 Keith Arthur, U. S. Geol. Surv. Geol. Atlas, Asheville folio (No. 116), pp. 9-10,1905. 

34 Keith Arthur, U. S. Geol. Sur. Geol. Atlas, Mount Mitchell folio (No. 124), p. 8, 1905 

35 Keith Arthur, U. S. Geol. Surv. Geol. Atlas, folios 143, 147 and 151, 1907. 



32 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

in general the same statements with reference to the ores as were made 
in the earlier folios. 

The magnetite deposits in the Roan Mountain quadrangle are 
described as being in the Cranberry granite near its contact with the 
Roan gneiss 36 . The statements as to the origin of the ores are the same 
as in the case of the Cranberry deposit. No special reference is made 
to the titaniferous varieties. 

Two items appeared in 1907, at about the time the last of Keith’s 
folios was issued. In one Eckel 37 remarked that the iron ores of North 
Carolina are of interest as of possible future use, but, he says, they are 
not “serious factors in the industry of to-day." He further states that 
“though deposits of brown hematite are known to occur at various 
points in North and South Carolina the ores to which attention must 
be paid in future are the magnetic ores of the western part of both 
States.’’ Hess 38 in the same volume, calls attention to the richness of 
some of the North Carolina magnetites in titanium and refers to the 
deposit north of Lenoir as being composed of menaccanite, magnetite 
and rutile, stating that it has been used in the manufacture of ferro- 
titanium. (See page 229.) 

Five years later, in 1912, Pratt 39 during the course of a rapid trip 
through Ashe County examined a number of the old mines and mine 
openings in the county and published the results of some of his obser¬ 
vations. He found the magnetites to be in lenses some of which may 
continue for long distances along the strike and dip. Others are smaller 
lenses in series. These are separated from each other by country rock 
or are connected with each other by thin seams of ore. Some deposits 
may be so small as to be of no commercial value, while others may be 
of great size. They lie in hornblende gneisses and schists and in mi¬ 
caceous schists, and are conformable with the country rock in strike 
and dip. 

The deposits are grouped in the three belts of Nitze. These Pratt 
calls the River belt, the Poison Branch belt and the Helton Creek belt. 
The most important deposits on each belt are described in some detail, 
but there are no statements made as to the possible origin of the ores. 
The details of the descriptions are referred to in the discussions of the 
various deposits in the body of this report, (pp. 134 to 160.) 

The author does not refer to the titaniferous ores of the county. 

%j 

Finally in 1913 appeared Singewald’s 40 report on the titaniferous 
ores in the United States, in which some of the North Carolina occur- 

36 Keith, Arthur. U. S. Geol. Surv. Geol. Atlas. Roan Mountain folio (No. 151), p. 10, 

1907. 

37 Eckel, E. C., Iron ores—North Carolina: U. S. Geol. Surv. Mineral Resources, 1906, 
p.88, 1907. 

38 Ibid., p. 530. 

30 Pratt, J. H., The mining industry in North Carolina during 1911 and 1912, N. C: 
Geol. and Econ. Survey, Economic Paper No. 34, pp. 64-73, Raleigh, 1914. 

40 Singewald, Jos. T. Jr., The titaniferous iron ores in the United States, their composi¬ 
tion and economic value: U. S. Bureau of Mines, Bull. 64, pp. 35, 80, 93, 1913. 



HISTORICAL REVIEW OF LITERATURE 


33 


rences are discussed with reference to their titanium content. It was 
inferred from a study by metallographic methods that in most cases the 
titanium is present as ilmenite, which is intergrown with magnetite, 
often so intimately that the two minerals cannot be separated by me¬ 
chanical means at a cost that will allow the purified ore to compete 
commercially with non-titaniferous magnetite. Later study of thin 
sections have shown that the titanium is mostly present as rutile in¬ 
stead of ilmenite. In the case of the Guilford County ore, however, 
observations indicated that the titanium mineral is in very coarse inter- 
growths, and experiments showed the possibility of the magnetic separa¬ 
tion of a product containing such a low content of titanium as to warrant 
its use in mixtures with titanium-free ores. 

Recently several papers by the present writer dealt with the origin 
of the Cranberry magnetite 41 , of the marble-magnetite ore 42 at Lan¬ 
sing, N. C., and of the titaniferous magnetites 43 in the western part of 
the State, and a fourth paper 44 described briefly the various types of 
magnetic ores in western North Carolina and East Tennessee. Since 
most of the material of these papers appears also in the present report, 
it is unnecessary to refer to them further. 

41 Bayley, W. S., The magnetite ores of North Carolina—their origin: Econ. Geol., 
vol. 16, No. 2, p. 142, 1921. 

42 Bayley, W. S., A magnetite-marble ore at Lansing, N. C.: Jour. Elisha Mitchell 
So., vol. 37, Nos. 3 and 4, p. 138, 1922. 

43 Bayley, W. S., The occurrence of rutile in the titaniferous magnetite of Western North 
Carolina and Eastern Tennessee: Economic Geology, vol. 18, No. 4. p. 382, 1923. 

44 Bayley, W. S., General features of the magnetite ores of Western North Carolina 
and Eastern Tennessee: U. S. Geol Surv., Bull. 735-G, 1922. 



PLATE 


i OISSVIHl OlOZOBIVd NVIXN091V 


NV3HDHV 



3 

£ 



oo- 


4i 

tu 

V) 

I 

5 

I 

<3 

£ 

I 

! 

4) 

V) 

.c: 

t. 

•s 

a 


w 

o 


! vi 


3 t-i bCLT i 
3 © ajt? S3 

2S& 

S-i O 

b£*s 

4J»P 

fl-3 C 
a; <g 3 

)W o 

■i M 

5l>^ 
■* ^ c 

- c3 
" L*o 

:Sn 
5 rfM 

■* Sm 

55 H 
" ft o 

5 X-h 

3 ® «3 

3 a) t-i 
3 <6 O 

- . Sh 

5 co £ 

^ rH ^ 



















































CHAPTER III. 

THE ORES 

GENERAL FEATURES 

The magnetic ores of the district under discussion, as has already 
deen stated, consist of three kinds: (1) those in which the ore com¬ 
ponent is magnetite; (2) those in which it is a mixture of magnetite 
and some mineral containing titanium, and (3) those in which it is a 
mixture of magnetite and hematite. At present only the non-titaniferous 
magnetites are of economic importance, although at once time the 
titaniferous ores were mined and formed the main supply for some of 
the forges in North Carolina. It was believed that they might furnish 
the principal source of iron for the eastern United States. However, 
with the introduction of modern methods of smelting, the value of the 
titaniferous ores diminished until in the latter portion of the last cen¬ 
tury all the openings into the deposits of these ores were abandoned. 
The magnetite-hematite ores have never been exploited. So far as is 
now known, their deposits are comparatively small and they are so 
far from railroads that the cost of getting them to the furnaces is pro¬ 
hibitive. Nevertheless, since the titaniferous and the hematitic ores 
constitute reserves of potential value, it is desirable to discuss them in 
some detail. 

Both the magnetites and the titaniferous magnetites are alike in 
general appearance and in their occurrence as lenses and veins in gneisses, 
schists and other crystalline rocks. Those in the mountain districts 
are associated with Archean country rocks. The country rocks asso¬ 
ciated with the deposits in the Piedmont area are quartzites, marbles, 
micaceous schists, slates, gneisses, and old volcanic lavas and tuffs 
which are younger than Archean, but probably older than Cambrian. 

Nitze 45 in his discussion of the magnetitic ores in North Carolina 
described them as occurring in belts, inferring that they are distributed 
along continuous lines. This inference may be correct in a broad way, 
i. e., the deposits are usually in zones parallel to the general structure 
of the region, but in a narrower sense they are in short discontinuous 
lines or series of parallel lines that may be close together in some places 
and widely apart in others. 

In some places the deposits are actually in line with one another, 
when they are situated along a zone of weakness in the country rock, 
usually a zone along which the schistosity is more pronounced than 
elsewhere. (See Plate I and Figures 13, 16 and 17.) In other places 
they are in schistose zones but not in the same plane. In these places 
the zone itself consists of a series of planes along which marked schis¬ 
tosity has taken place, but the loci of maximum weakness are not always 

«Nitze, H. B. C., Iron ores of North Carolina: N. C. Geol. Surv. Bull. No. 1, pp. 239, 
Raleigh, 1893. 




36 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

in the same plane. The deposits may be within the limits of a com¬ 
paratively narrow belt crossing the country, but not along the same 
line within the belt. Their long axes may have the same direction, but 
the projection of their strikes are parallel. 

The magnetite-hematite ores are not so well known as the magnetites 
and the titaniferous ore, and their method of occurrence has not been 
so*carefully studied. They consist of mixtures of magnetite and hema¬ 
tite in widely different proportions. They vary in appearance from 
flinty, purple, dense, vein-like masses to fine granular and micaceous 
aggregates, resembling the specular hematites of the Lake Superior 
region, that seem to lie in beds, interlayered with igneous rocks that 
are believed to be Algonkian volcanics. 

MAGNETITES 

The magnetite ores include those magnetic iron ores in which 
titanium is present in such small quantity as to give practically no 
trouble in the blast furnace. They occur as lenses or veins in the old 
crystalline rocks of the Mountain district in North Carolina and East 
Tennessee and of the Piedmont district in North Carolina. (See Plate 
I and Figures 13, 16 and 17.) Though associated with large quantities 
of hornblende, they are not accompanied by basic intrusives as is the 
case with the titaniferous types, but are rather characterized by the 
presence near them of pegmatites. 

The magnetite deposits have furnished most of the ore that has 
been mined in North Carolina. Some of them were worked as early as 
1802 for use in Catalan forges. The famous Cranberry ore which is a 
non-titaniferous magnetite produces iron exceptionally low in phosphorus, 
and for this reason supplies a demand that cannot be as well supplied 
by metal from any other source. All the magnetites in the district fall 
within the Bessemer limit and most of them well below it. 

All the magnetites, as has been said, occur in old crystalline rocks. 
Most of them are in granites and crystalline schists. These are referred 
to as the siliceous type. Those in the Piedmont district are in crystalline 
schists associated with quartzites. These also are of the siliceous type. 
One deposit in Ashe County, and perhaps several others, is in marble. 
This is referred to as a marble-magnetite ore. 

The first type is the usual one for the district. It consists essen¬ 
tially of a mixture of hornblende and magnetite, often cut by small 
veins of nearly pure magnetite, or of a mixture of magnetite, horn¬ 
blende and epidote, which occurs in a more or less distinct vein follow¬ 
ing the obscure schistosity of granitic rocks or the more evident struc¬ 
ture of schists. 

The second type consists of granules and small lenses of magnetite 
in a white marble. It is represented by a few deposits near Lansing, 
one of which is being worked by the only active mine in the countv. 

•7 


CHAPTER IV. 

SILICEOUS MAGNETITES 

CHARACTER 

Under the name siliceous magnetites are included those non- 
titaniferous magnetic ores that occur associated with siliceous rocks to 
distinguish them from those that are associated with marble. They 
constitute by far the greater portion of the iron ores that are in the pre- 
Cambrian areas, and those of greatest value per unit, since they are 
nearly free from phosphorus and sulphur. Unfortunately most of them 
are found in comparatively small deposits and the magnetite in them is 
so intimately mixed with silicates that some form of beneficiation must 
be applied to them before they are fit for the furnace. As taken from 
the ground they are low in iron, except in a few cases, but when con¬ 
centrated they furnish an ore that is in great demand for special pur¬ 
poses. 

Because of their differences in character and associations the de¬ 
posits in the Mountain district and in the Piedmont Plateau are dis¬ 
cussed separately. The most striking difference in the two groups of 
deposits is the association of epidotized pegmatites with the mountain 
magnetites and of talcose schists with those occurring in the Piedmont 
area. 


DEPOSITS IN THE MOUNTAIN DISTRICTS 

GEOLOGY 

The rocks of the Mountain district are crystalline schists, gneisses 
and igneous rocks sharply infolded with conglomerates, shales, sand¬ 
stones, limestones, and one layer of amygdaloidal basalt. Ti3>i 
in places, are metamorphosed to slates, quartzites, marbles and various 
sandy schists. The sediments are believed to be of Cambrian and Ordo¬ 
vician age. They are intersected here and there by diabase dikes. 
(See Plate I.) The schists, gneisses and granites are pre-Cambrian. 

Since the ore veins are not known to occur in the Cambrian or 
Ordovician rocks, attention need be directed only to those of pre-Cam¬ 
brian age. 

Keith 46 , who has mapped nearly all of the area with which we are 
concerned, concludes that the sequence of the pre-Cambrian formations 
in the Cranberry area is as follows: 

46 Keith, Arthur, U. S. Geol. Survey Geol. Atlas. Cranberry (No. 90), Asheville (No. 
116), Greeneville (No. 118), Mount Mitchell (No. 124), and Roan Mountain (No. 151), 
folios, 1903-1907. 



38 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Generalized table of pre-Cambrian rocks in the Cranberry area 

CAMBRIAN 

ALGONKIAN 


Metarhyolite.Grayish metarhyolite and rhyolite porphyry. 

Flattop schist.Gray and black schist, proably altered andesitic 

rocks. 

Montezuma schist.Blue and green epidotic schist, probably altered 

basalt, and amygdaloidal basalt. 

Linville metadiabase.Altered greenish diabase and gabbro. 


ARCHEAN 


Igneous Rocks 

Beech granite.Coarse, reddish or porphyritic light granite. 

Blowing Rock gneiss.Chiefly dark, coarse, porphyritic gneiss. 

Cranberry granite.Mainly granite and granite-gneiss. 

Soapstone, serpentine and dunite.Soapstone and serpentine altered from perido- 

tite and pyroxenite. 

Roan gneiss.Chiefly hornblende gneiss and diorite. 

Metamorphic rocks of unknown origin 

Carolina gneiss.Mica gneiss and mica schist, of unknown origin. 

Includes also other gneisses and schists and 
various igneous rocks and small lenses of 
marble. 

In addition there are small areas underlain by gabbroitic rocks 
which Keith regards as Triassic, but which, for reasons that will be dis¬ 
closed later (pages 41 to 44), are now considered as a portion of the Roan 
gneiss series or perhaps as equivalent to the meta-gabbro which Keith 47 
has differentiated from the Roan gneiss on the map of the Asheville 
quadrangle, but which he thinks “was probably formed at about the 
same age as, or perhaps slightly later than, the Roan gneiss.” 

In the other quadrangles the variety and succession of formations 
is very much the same as in the Cranberry quadrangle, except that in 
some of them a few more granites have been differentiated and given 
distinct names. 

These rocks are folded into a complicated series of sharp anticlines 
and synclines, the outcrops of which cover irregularly shaped areas 
with a strong tendency to a NE.-SW. elongation. In many places the 
formations appear on the surface as narrow parallel bands more or less 
curving, but having a general NE.-SW. trend. (Compare map, Plate I.) 
In other places the granites and the Roan gneiss occupy broad areas, 
but they enclose narrow bands of other formations which have the usual 
trend. 


47 Keith, Arthur, U. S. Geol. Surv. Geol. Atlas, Asheville folio (No. 116), p. 3. 













SILICEOUS MAGNETITES 


39 


In addition to folding, faulting is also an important structural 
feature of the pre-Cambrian rocks, though it is not as apparent as in 
the Cambrian and Ordovician sediments where disturbance of the 
known orderly alternation of beds is easily detected. Faults can be 
easily recognized when they occur at the contacts of the pre-Cambrian 
and the Cambrian areas, but within the pre-Cambrian areas they can 
be seen only under very favorable conditions. The fault planes strike 
in the same direction as the folds, i. e., usually NE., and dip to the 
southeast. 

All of the pre-Cambrian rocks are also strongly schistose, as the 
result of movements developed during the folding and faulting of the 
district. The strike of this schistosity is approximately parallel to the 
strike of the fold in which the rocks are involved, being straight where 
the axis of the fold is straight and curved where the axis is curved. 
For the most part the strike is to the northeast, which is the strike of 
the most numerous folds, and the direction of the trend of the nar¬ 
row areas of the different rocks exposed on the surface. Where the 
folds curve, the strips of exposed rock also curve and their strikes 
curve correspondingly. Since the schistose planes are planes of weak¬ 
ness in the rocks exhibiting schistosity, it is plain that intrusions 
into them of any kind, whether of dikes or veins, will tend to follow 
these planes rather than cut across them, provided the intrusion was 
made after the schistosity was produced. It is for this reason, probably, 
that all, or nearly all, the ore veins of the district follow the schistosity 
of the rock in which they occur, and extend in the direction of the struc¬ 
ture of the country. 

The only two formations that need further descriptions than the 
brief ones given in the table above are the Roan gneiss and the Cran¬ 
berry granite. Both formations are complex in that they consist of a 
series of rocks rather than a single rock. The members of each forma¬ 
tion, however, resemble each other much more than they do any of 
the members of the other formations. The Cranberry granite is a 
series of light colored acid gneisses and the Roan gneiss a series of dark 
colored basic gneisses. 

ROAN GNEISS 

The Roan gneiss, according to Keith, “consists of a great series of 
beds of hornblende gneiss, hornblende schist, and diorite with some 
interbedded mica schist and mica gneiss. The liornblendic beds are 
dark greenish or black in color, and the micaceous beds are dark gray.” 
The micaceous beds range in thickness from a few inches to 50 or 60 
feet and they are abundant near contacts with the Carolina gneiss, 
where their presence is explained as due either to intrusion of the Caro¬ 
lina gneiss by dikes of the magma that produced the beds of the Roan 
gneiss, or to the infolding of layers of the former with the latter. 


40 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

The hornblendic members of the series range from an inch or two 
lo thousands of feet in thickness. Hornblende schist makes up a large 
part of the series. It consists almost entirely of hornblende with a 
very little biotite, feldspar and quartz, and is interbanded with the 
hornblende gneiss, which is said to differ from the schist in being inter- 
layered with sheets of quartz and feldspar. Beds of coarse diorite or 
gabbro are also common at some places, and these are also interlayered 
with the schists and gneisses. It is probable that the formation was 
originally a series of interlayered gabbros, diorites and perhaps other 
intermediate and basic rocks which became metamorphosed by defor¬ 
mation processes and had produced in them a complete recrystallization 
of their components into new ones. Garnet was a common product of 
this process, so that many of the gneisses, schists and more massive, 
dioritic beds are now full of little crystals of this mineral. Excellent 
exposures of the series are to be seen on the Carolina, Clinchfield and 
Ohio Railroad between Forbes and Toeeane and in the cuts on the East 
Tennessee and Western North Carolina Railroad one mile south of 
Cranberry. 

About three-quarters of a mile east of Forbes in Mitchell County, 
N. C., is a cut through a diabasic rock that weathers to great nodules. 
Beyond this to the east are black gneisses and beyond these are exposures 
of a fine grained purplish-black, very slightly schistose rock that appears 
to be a sill in the more schistose gneisses. 

The diabasic rock now consists of large broken plagioclase crystals, 
enlarged at their ends by the addition of new feldspar, lying in a matrix 
of calcite, serpentine, amphibole, biotite, chlorite, epidote, quartz, 
magnetite, and here and there remnants of pyroxene. The grouping 
and distribution of these secondary minerals suggest an origin from an 
olivine diabase. 

The purplish-black sill in the gneisses is very much like the sill-like 
mass on Roaring Creek (page 218), which is also mapped by Keith (in 
the Roan Mountain folio No. 151) as Roan gneiss. The rock is com¬ 
posed mainly of a medium-grained granular aggregate of fresh and com¬ 
pact green hornblende, fresh striated and unstriated feldspar, quartz 
and lenses of granular garnet. Scattered among these are comparatively 
large flakes of reddish-brown biotite, numerous small grains of mag¬ 
netite and large and small nests of calcite. The larger grains exhibit 
a slight tendency to elongation in a common direction. The small 
grains, however, are not noticeably elongated, but they are often grouped 
into little lenses that have a common orientation, causing the rock’s 
sehistosity. This is particularly noticeable in the case of the garnet, 
which is in very much elongated lenses composed of many little round 
grains of colorless garnet, numerous grains of quartz, small particles of 
magnetite and a few flakes of biotite. Little nests of calcite are scat- 


SILICEOUS MAGNETITES 


41 


tered throughout the rock, but they are larger and more abundant near 
the garnets than elsewhere. Thin sections of the gneisses differ from 
those of the more massive layers in containing much more quartz and 
often much more brown biotite. 

The interlayering of the massive and schistose beds is well exhibited 
in the railroad cut south of Cranberry. Here there are hornblende 
schists, amphibolites, garnetiferous hornblende gneisses and massive 
gabbroitic rocks. The schistose rocks consist of green amphibole, 
plagioelase, brown biotite and quartz in widely varying proportions to¬ 
gether with small quantities of epidote, spliene, apatite and ilmenite. 
Garnet is abundant in some specimens and is entirely absent from others. 
It is nearly always present where the rock shows evidence of being 
crushed. Nearly all plagioelase grains are granulated on their edges, 
or are shattered, and many grains show curved twinning striations. 
New feldspar in small grains is often found with granular green horn¬ 
blende making a groundmass in which remnants of the original feldspars 
are embedded. In some specimens the diabasic texture can be recog¬ 
nized, even in distinct schists. In other specimens the entire rock is 
made up of small granules of amphibole, feldspars and quartz. All 
the amphibole-plagioclase schists and granites are believed to be sheared 
diorites, diabases, or gabbros. 

A few schists are now composed of green amphibole, quartz and 
fresh untwinned feldspar and others of reddish-brown or green bio¬ 
tite, quartz and feldspar. In some of the biotite schists the biotite 
is in large flakes as in an ordinary biotite schist and in others is limited 
to the crush debris between quartz and feldspar. In the crush debris 
it occurs as comparatively small wisps. It was evidently a metamorphic 
mineral formed while the rock was being crushed. The original form 
of the richly micaceous schist is not known. It may have been a mica 
diorite. 

BAKERSVILLE GABBRO 

The “Bakersville gabbro” which is mapped as accupving a small 
area south of Cranberry is described by Keith 48 as being in a rudely 
lenticular mass lying along the foliation planes of the Roan gneiss. He 
states that it exhibits no evidence of dynamic metamorphism, although 
the surrounding rocks are all metamorphosed, in many places to an 
extreme degree. Consequently, he concludes, it must have been in¬ 
truded into the Roan gneiss after the last deformation of the region and 
therefore must be younger than the end of Paleozoic time. Since it is 
thought to be similar in general character to the Triassic diabases and 
gabbros of the Piedmont Plateau area, he assigns it to this age. How¬ 
ever, in the text of the Asheville folio 49 , he describes a “very basic rock 

48Keith, Arthur, U. S. Geol. Surv. Geol. Atlas, Cranberry folio (No. 90), p. 5, 1903. 

49 Iveith! Arthur, U. S. Geol. Surv. Geol. Atlas, Asheville folio (No. 16), p. 3, 1904. 




4 % MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

of the same general appearance as the massive portions of the Roan 
gneiss, but . . much less schistose and gneissoid,” which in places is 
speckled with garnets, and states that it “was probably formed at 
about the same age as, or perhaps slightly later than the Roan gneiss.” 
He designates it as a “metagabbro.” The Bakersville gabbro is iden¬ 
tical with the “metagabbro" in general appearance, and if the latter is 
pre-Cambrian in age, the former is also. The “Bakersville gabbro”, 
according to Keith, is a dense, dark rock which on weathered surfaces 
has a reddish-brown or rusty appearance. Its texture is said to be mas¬ 
sive and granular in most specimens, but to be ophitic in a few. Plagio- 
clase occurs sparingly in porphyritic crystals and garnet is common. 

All the varieties of the Bakersville gabbro described by Keith as 
occurring in the area south of Cranberry were observed by the writer 
and in addition several others. One was a porphyritic variety with 
numerous phenocrysts of plagioclase an inch in length. In some places 
fine-grained black schists are interleaved with the more massive meta- 
gabbros. In some places the lower portions of the massive layers 
grade into schistose phases, but it was not certain that the schists were 
made from the massive phases by shearing. 

In the field the massive beds showed no evidence of having been 
subjected to dynamic metamorphism, in spite of the fact that there 
had been developed in them great quantities of garnet. When, how¬ 
ever, their thin sections are viewed under the microscope it is very 
apparent that none of them have escaped metamorphism. All are full 
of metamorphic minerals and all exhibit more or less clearly signs of 
crushing. In some of them there remain a few remnants of augite in 
the midst of an aggregate of grains of green hornblende, but in most 
there is no trace of pyroxene remaining. The rocks now consist of 
plagioclase, green hornblende, and a little quartz, biotite, sphene, epidote, 
ilmenite or magnetite and calcite. In some specimens is a little tour¬ 
maline and in others some corundum. 

The plagioclase is fractured and in some instances its twinning bars 
are curved and numerous grains show a wavy extinction. Frequently 
the edges of crystals are granulated and in some cases what were origin¬ 
ally phenocrysts of plagioclase are now aggregates of striated and un- 
striated feldspar grains, a few grains of quartz, a few or many wisps of 
brown biotite and an occasional crystal of garnet. The hornblende is 
in masses of small, closely crowded granules, in some places intermingled 
with granules of quartz and unstriated feldspar, and in others cemented 
by feldspathic material which, in the section, is continuous over com¬ 
paratively large areas. In most cases the hornblendic and feldspathic 
portions of the sections suggest a diabasic texture, but in other cases the 
original texture appears to have been granitic. 

Most specimens contain also garnet in addition to the minerals 
already mention d. In some the garnets are in the form of crystals 


PLATE II. 



( A ) Photomicrograph of Bakersville gabbro, near Cranberry, N. C. Area en¬ 
closed in dotted line is garnet. Black is magnetite and gray hornblende. The smaller 
white areas are fresh feldspar and quartz, the larger white areas in upper part are 
epidotized plagioclase. Ordinary light. X50. 

(B) Photomicrograph of ore from Peg Leg mine, Carter County, Tenn. Black 
is magnetite and gray pyroxene with some uralite. The white areas in the magnetite 
are holes, those in the pyroxene are granular quartz. Ordinary light. X30. 





44 


MAGNETIC IRON ORE f i OF EAST TENN. AND WESTERN N. C. 


of the same size as the other rock constituents and are scattered irregu¬ 
larly among them, but in most specimens they are in large grains many 
times larger than any other component except the feldspar phenoerysts. 
(Plate II, A.) All the garnets have the sieve structure which is indi¬ 
cative of metamorphic origin. In some specimens brown biotite is abun¬ 
dant and amphibole is present. In these quartz is more common than 
in the hornblendic phases. 

In nearly all sections there can be detected crush zones, in which 
all the components are in small grains forming a schistose mosaic con¬ 
taining more biotite than is present elsewhere in the sections. 

An analysis of a non-garnetiferous variety with a diabasic texture 
from Cranberry Creek, made by Dr. J. I. D. Hinds of the Tennessee 
Geological Survey, gave: 

Analysis of “Bakersville gabbro” from near Cranberry, N. C. 


Silica (Si0 2 ). 46.80 

Alumina (AI 2 O 3 ). 16.65 

Ferric oxide (Fe^Ch). 13.52 

Ferrous oxide (FeO). 5.04 

Magnesia (MgO). 4.01 

Lime (CaO). 8.32 

Soda (Na 2 0). 2.86 

Potash (K 2 0).80 

Phosphorus pentoxide (P 2 O 5 ). 1.41 

Water above 110°.50 


99.91 

This corresponds to a hessose in the chemical classification. It is 
a metadiabase in the more familiar classification. Other specimens 
would give other results, but all the massive beds in the series would 
probably be proven by analysis to have the chemical compositions of 
gabbros, diorites or diabases. 

From the microscopic study of sections it has been learned that all 
of the massive rocks in the “Bakersville gabbro" area are similar to the 
massive beds in the Roan gneiss series. They have suffered the same 
kind of alteration as the beds in the Roan gneiss and have suffered the 
same degree of metamorphism. They cannot be regarded as unmeta- 
morpliosed Triassic rocks. They must be regarded as a part of the 
Roan gneiss series, and probably as equivalent to Keith’s metagabbro 
of the Asheville area. 

CRANBERRY GRANITE 

Keith 50 writes that the Cranberry granite formation “consists of 
granite of varying texture and color, and of schists and granitoid gneisses 
derived from the granite. Included in the formation are small or local 
beds of schistose basalt, diorite, hornblende schist and pegmatite . . . 


60 Keith, Arthur, U. S. Geol. Surv. Geol. Atlas, Cranberry folio (No. 90), p. 3, 1903. 















SILICEOUS MAGNETITES 


45 


The granite is an igneous rock composed of quartz and orthoclase and 
plagioclase feldspar with biotite, muscovite and occasionally hornblende 
as additional minerals." It is described as varying from a fine, even- 
grained mass to a coarse porphyritic phase. It suffered great changes 
during the deformation of the region which resulted in the production 
of schists and gneisses with a fairly uniform dip over large areas. “The 
results varied in extent from rocks with no change ... to those com¬ 
pletely altered into siliceous schists and gneisses . . . Thin parallel 
layers and striations composed of different minerals are of frequent 
occurrence, and the most extreme schists bear no resemblance to the 
original rock." 

Detailed examination of the Cranberry granite in the area around 
Cranberry proves conclusively that the formation is complex. Its 
greater part consists of granite, gneiss and schists like those described 
by Keith, but in addition there are present other schistose members 
which cannot be regarded as sheared phases of the granite. 

The ore vein at the southeasternmost opening of Smoky Mountain 
(Smoky No. 1) at Cranberry is in Cranberry granite. On the hanging, 
or southwest wall, the granite is platy and is foliated with layers of horn¬ 
blende gneiss and with others of a fine-grained light-colored gneiss that 
looks almost like a flow rhyolite. The whole is puckered and folded. 
(Plate XVI, A.) As the distance from the contact with the vein in¬ 
creases the inter-foliated gneisses apparently become less abundant 
and the light-colored, coarse-grained granite becomes more homogeneous 
and less schistose, though it still exhibits schistosity several hundred 
yards from the contact. Certain ledges, however, show a porphyritic 
granite which in many places is sheared to an augen-gneiss. The 
foot-wall rock is not visible, but it is known that it also consists of 
Cranberry granite. 

The fine-grained, thinly banded light-gray rock near the contact 
that has been referred to as resembling a rhyolite, when studied in thin 
section is found to be schistose and minutely contorted. It is so thor¬ 
oughly crushed that little of its original structure remains. It consists 
now of streaks of a very fine mosaic of elongated quartz, orthoclase 
and epidote grains with here and there little wisps of muscovite which 
curve around comparatively large fragments of plagioclase, mainly 
oligoclase, that suggest shattered phenocrysts. In some instances the 
large feldspar fragments are crushed into numerous small ones forming 
an aggregate of the same form as the original fragment. Orthoclase is 
present in small quantity in the enveloping mosaic and to some extent 
as larger fragments, but it seems to have suffered more decomposition 
than the plagioclase and is difficult to identify. 

Specimens taken from points farther from the contact are not so 
thoroughly crushed. The epidote is confined to grains of plagioclase, 


46 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

and is not a component of the mosaic enveloping the feldspar. The 
mosaic is here mainly quartz and feldspars with a few flakes of biotite. 

Still farther from the contact the feldspar is in larger fragments, 
some of which appear to be phenocrysts that have been merely abraded 
on their corners. Many of these have been enlarged by the addition 
of microeline, and some of the same mineral has apparently developed 
in the crush mosaic of feldspar and quartz. Biotite is a little more 
abundant in the sections examined, but is not common. Epidote is 
absent, except in an occasional nest of grains in certain streaks through 
the mosaic where the crushing has been especially thorough. 

Throughout all the sections there has been considerable regenera¬ 
tion of feldspar and quartz.* Fresh microeline and fresh plagioclase are 
quite common in the interstices between the elongate grains of the mo¬ 
saic and fresh clear microeline not only surrounds the large cloudy 
plagioclase fragments, enlarging them, but it also saturates their masses. 

These rocks are very much like specimens of the lighter colored 
ph ases of the Cranberry granite elsewhere. For instance at the top of 
Smoky Mountain, southeast of the Smoky No. 1 opening, light and 
dark gneisses are interlayered. In thin section the lighter rock is seen 
to be crushed in the same manner as the rock near the opening. There 
are large fragments of orthoclase and plagioclase, and lenses with plagio¬ 
clase nuclei, surrounded by a mosaic of quartz and feldspar with an 
occasional biotite flake, running through which are streaks of muscovite 
fibers and of a fine quartz mosaic. Epidote in grains and short prisms 
and in nests of grains are scattered through the mosaic, and in many 
instances the larger quartzes of this mosaic exhibit strain shadows. In 
other places the light-colored gneisses resemble crushed rhyolite. They 
all contain a little magnetite in small grains and more or less epidote 
which has evidently been derived from plagioclase. The epidote that 
is in nests is probably the alteration product of grains of plagioclase that 
are in their original position; the grains and short prisms are particles 
that have been intermingled with other components of the mosaic by 
movements in the rock mass. 

Some of the layers are entirely different from the fine-grained 
varieties that have been described, though nearly all show that they 
have been crushed and sheared. In most cases these processes have 
resulted in a fine-grained and banded schist retaining very little evi¬ 
dence of its original structure. In other cases the crushing is less com¬ 
plete and the rock is now a coarse-grained gneiss. Such a rock occurs 
on the road running south of Shell Creek, Tenn., where there is a coarse¬ 
grained biotite gneiss streaked with pegmatite. Under the microscope 
this rock is seen to have been subjected to strong stresses, as almost 
every grain of its quartz exhibits strain shadows. Orthoclase, micro- 
cline, oligoclase, and other undetermined plagioclase are abundant. 


SILICEOUS MAGNETITES 


47 


Quartz is subordinate. The dark components are brown mica, partially 
changed to light-green amphibole, and a small quantity of additional 
green amphibole that appears to have been derived from a more com¬ 
pact amphibole or from pyroxene. 

The Cranberry granite is evidently a crushed and sheared complex 
of acid feldspatliic rocks varying in composition to some extent, though 
perhaps not widely. Their layering may be an original structure or, 
as is more probable, it may be a secondary result of shearing. In some 
cases the alternation of darker and lighter layers is due to the intrusion 
of feldspatliic veins, perhaps pegmatites, along their schistose planes, 
but in other cases it seems to be the result of shearing in a nearly homo¬ 
geneous rock. 

With the light-colored layers, which constitute by far the larger 
part of Keith’s Cranberry granite, are also much more basic layers. 
Most of these are regarded by Keith as portions of the Roan gneiss 
which have been intruded into the Cranberry granite, since they are 
much more common near the borders of the granite areas than in their 
interiors. The few specimens seen by the writer have suffered less pro¬ 
found crushing than have the specimens of the granite that have been 
studied, but this may not be a general fact. In the very few thin sections 
examined the dark layers, while now very largely amphibolites or horn¬ 
blende schists nearly all retain traces of a gabbroitic or a diabasic struc¬ 
ture. 

Farther south, near the crest of Smoky Mountain the formation con¬ 
sists of coarse-grained and fine-grained light rocks and fine-grained 
dark rocks interlayered, with here and there layers of coarse pegmatite. 
Some of the fine-grained light rocks are very much like the rhyolite 
referred to above in the description of the hanging at Smoky No. 1. 
Although only small exposures can be seen, nevertheless the impression 
is unescapable that what Keith calls the Cranberry granite is an intrusive 
in a series of basic gneisses and schists. In other words, the impression 
gained from a study of the Cranberry granite area is to the effect that 
we have here a repetition of the conditions that prevail in the magnetite 
district in the highlands of New Jersey, where a series of dark femic 
gneisses and schists—known as the Pochuek gneisses—were intruded 
parallel to their schistosity by alkalic granites—the Losee and Byram 
gneisses. 

RELATIONS BETWEEN ROAN GNEISS, CRANBERRY GRANITE AND 

OTHER ROCKS 

The oldest rocks in the mountains are interbedded mica schists, 
mica gneisses and fine-grained granites which are grouped together 
under the name Carolina gneiss. They are regarded as the oldest be¬ 
cause very widely distributed in such a way as to suggest a mass into 
which all the more distinctly igneous rocks appear to be intruded. “The 


48 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Roan gneiss appears to cut the Carolina gneiss, but the contacts are so 
much metamorphosed that the fact cannot be proved. The narrow 
dikelike beds of the former in the latter support this view, as well as 
the fact that the diorites are less altered than the Carolina gneiss and 
so appear to be younger. Moreover, narrow beds of diorite and horn¬ 
blende-gneiss entirely similar to these cut the Carolina gneiss in adjoin¬ 
ing areas toward the south.” 51 

The Roan gneiss is believed to be older than the Cranberry granite 
because, although the prevalent metamorphism of the region and the 
heavy forest cover make it difficult to obtain precise evidence of eruptive 
contact with the adjoining formation, such contacts as can be seen 
show that the granite clearly cuts into the Roan gneiss and the Caro¬ 
lina gneiss. If the cutting granite is the same as that constituting the 
greater part of the Cranberry granite formation, this formation on the 
whole must be younger than the Roan gneiss. 

All the other formations, except the soapstone, intrude the Cranberry 
granite or intrude rocks that in turn cut the granite, and are thus re¬ 
garded as younger than the granite. 

The soapstone formation occurs in numerous rather small areas 
scattered through the areas occupied by the other rocks and is of little 
importance in connection with the non-titaniferous magnetite ores. 
The formation comprises peridotites, dunites and their alteration prod¬ 
ucts, serpentine and soapstone. Keith declares that the members of 
the “formation break through and across the Roan gneiss and in some 
places are found as inclusions in the Cranberry granite. Consequently 
the formation is concluded to be of intermediate age between the gneiss 
and the granite, although it is not markedly schistose. It is possible, 
however, that the peridotites and dunites may be much younger than 
the Roan gneiss and that the supposed inclusions in the Cranberry 
granite may be intrusions into the granite rather than inclusions. If 
this is so the soapstone may be even much younger than the granite. 

ORE VEINS 
VEIN-FILLING 

The ores of all the deposits in the Mountain district are granular 
mixtures of pyroxene, hornblende and magnetite or of magnetite, horn¬ 
blende, epidote, and quartz. The pyroxene and magnetite are usually 
cracked or shattered and the quartz is largely granulated. The epidote 
where it occurs, is an alteration product of plagioclase. These rather 
low grade ores occur in veins from a few inches to many feet wide tra¬ 
versing gneisses or gneissoid granites parallel to their schistosity. Most 
of the veins dip at high angles. In many places they swell into lenses 
several hundred feet wide and in others pinch to very narrow streaks. 


51 Keith, op. cit., p. 2. 




PLATE III. 



Polished surface of portion of vein-filling, Cranberry mine, Cranberry, N. C., 
showing interlayering of ore and gangue. The darkest bands are hornblende, the 
mottled black and gray ones layers of hornblende and magnetite intermingled (ore), 
the dark gray ones mixtures of hornblende and epidote, the light gray epidotized 
feldspar, and the white ones quartz veins. (Natural size). 


50 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


The richer portions of the veins, constituting the merchantable 
ore, occur as irregularly shaped masses cutting through the leaner vein 
matter and swelling into lenses, that are usually joined by streaks of 
rich ore. No general statements can be made as to the relation between 
ore and vein matter that will apply to all deposits, since in most places 
these relations can not be studied because of the very slight development 
of most of the deposits. Only in the deposit at Cranberry in Avery 
County, N. C., has extensive underground work been done, and, con¬ 
sequently, nearly all statements concerning the nature of the ore and of 
the vein-filling and the relations of these to one another, must be based 
on observations made at the Cranberry mine, and all conclusions as to 
the origin of the ore must be founded on the facts noted in this mine. 
There is no reason to suppose that the other magnetite deposits in the 
Mountain district are any different from that at Cranberrv either in 
character, associations or origin, and, consequently, they are all grouped 
together as similar. Only the deposit at Cranberry has been studied 
in detail. 

The veins in which the ore occurs comprise more or less banded 
mixtures of pegmatite, epidotic gneisses, hornblende schists and len¬ 
ticular masses of a mixture of hornblende and magnetite, in places cut 
by small veins of magnetite. (See Plates III, IV and V.) The mixtures 
of hornblende and magnetite constitute the lean ores and when cut by 
veins of magnetite the rich ores. In a few places the magnetite veins 
are thick enough to furnish fragments that can be picked by hand from 
the run of mine and saved for high-grade ore. 

The veins extend for variable distances. At Cranberry the vein 
has been traced continuously for 6,400 feet and that on the Ballou 
property in Ashe County, N. C., for at least half a mile. In most places 
the veins are located by but few exposures and a very few openings, 
so that their lengths are undetermined, but usually the exposures and 
openings are in lines following the schistosity of the rocks in which they 
occur, so that whether the individual veins are long or short they occupy 
zones which are narrowly limited in width and which in some cases are 
several miles long. The zone in which the Cranberry vein is situated 
is at least 25 miles long. So far as is now known all the veins follow 
the structure of the country, which is the same in direction as that of 
the schistosity of the rocks. They appear to be much more common 
in the gneissoid granites than in the schists of the region, but this seem¬ 
ing preference for the granite may be due to the fact that most of the 
veins that have been studied are in Mitchell, Avery and Ashe counties 
where the Cranberry granite or a closely allied gneiss is the pre-Cambrian 
rock that is most widely exposed. 


PLATE IV. 



Polished surface of portion of vein-filling, Cranberry mine, Cranberry, N. C., 
showing association of ore with hornblende. The light bands are epidotized peg¬ 
matites, the black mineral is hornblende, and the gray one, in the lower part of the 
figure, is magnetite. The mixture of magnetite and hornblende is the ore. At the 
bottom of the figure is a small bit of epidote-hornblende gneiss. (Natural size.) 




52 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


THE ORE 

The ore is a mixture mainly of magnetite and hornblende with minor 
quantities of quartz, epidote, feldspar, garnet, calcite and a few other 
substances. A small quantity of the contents of the veins may be 
hand-picked and shipped as good ore, but most of the material that 
can be mined economically is comparatively low-grade, containing about 
40 to 42 per cent of iron. The larger portions of the veins are too low-grade 
to enter the furnace and must be concentrated before it can be used. 

Since the Cranberry mine is the only mine operating on the siliceous 
magnetites its ore must serve as a sample of the ore of the district. In 
1892 the crude ore taken from the mine anedyzed as in column 1, and 
after hand-cobbing as in column 2. A representative analysis of cobbed 
ore, selected by the chemist of the Cranberry Furnace Company, is 
shown in column 3. 


Analyses of crude and cobbed ore, 

Cranberry mine. 

Avery County, N. C. 


I 

2 

3 

Silica (Si0 2 ). 

20.97 

20.74 

23.50 

Alumina (AI 2 O 3 ). 


1.55 


Iron (Fe). 

45.93 

48.57 

46.55 

Manganese (Mn). 

.31 


.46 

Copper (Cu). 



.004 

Lime (CaO). 

10.10 

8.01 

8.94 

Magnesia (MgO). 

1.43 

1.74 

1.68 

Sulphur (S). 

.02 


.041 

Phosphorus (P). 

Tr. 

.0093 

.0068 

Titanium dioxide (TiCC). .. 



.039 


Foi merly tfie or e was concentrated by electro-magnets, but the 
process employed was not satisfactory and it was abandoned. In 
1920-21 the ore was shipped direct to the furnace. This, however, 
resulted in such a large loss of material that measures are being taken 
to develop a cheap and efficient method of concentration that will save 
much of the magnetite in the crude ore that is now being wasted. 

A selected sample of the Cranberry ore was analyzed by Mr. J. 
G. Fairchild of the U. S. Geological Survey with the result shown on 
page 1C2. There was in it no V 2 0 3 , Cr 2 0 3 , BaO, SrO, or F. An analysis 
of a selected sample of the Peg Leg ore (page 127) gave similar results. 
Both analyses showed small quantities of MnO and of Ti0 2 . They 
differ from analyses of the magnetite from the gneisses in New Jersey 
in showing less Ti0 2 , no V 2 0 3 and no F. 

The ore from different portions of the veins presents different as¬ 
pects. The greater part consists mainly of hornblende and magnetite, 
but in a few places pyroxenic ores are found and in other places ores 
containing large quantities of garnet. 

One type of ore is represented by that of the Kirby mine in Ashe 
County, N. C., and of the Peg Leg mine in Carter County, Tenn. These 



















PLATE V. 



Polished surfaces of two specimens of pegmatite and ore, from vein at Cran¬ 
berry mine, Cranberry, N. C. The white is feldspar partially epidotized (light-gray), 
the black is hornblende, and the dark gray magnetite. The magnetite is always inti¬ 
mately associated with the hornblende. The mass in the lower left-hand corner of 
both specimens is ‘rich ore.’ In the lower specimen extensions of the hornblende- 
magnetite mixture appear to have penetrated the pegmatite. (Natural size). 



54 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


ores consist mainly of green pyroxene and magnetite—the former in 
large anhedrons that often possess smooth curved boundaries. (See 
Plate II, B.) They are slightly pleochroic in green and yellowish-green 
tints and are crossed by many cleavage cracks, by the diallage parting 
and by many irregular fractures that are filled by quartz and calcite. 
The magnetite is in irregular masses between the pyroxene grains. 
Where magnetite is not present its place is taken by quartz or by quartz 
and calcite together with a few fibers or wisps of uralite, and an occa¬ 
sional grain of epidote, all of which appear to be secondary. In the 
Kirby mine ore the pyroxene encloses a series of very fine needles and 
plates, like the rutile needles and plates often observed in the augitic 
component of basic igneous rocks. In this ore the magnetite and py¬ 
roxene are cracked, as in the ore of the Peg Leg mine, but the cracks 
are filled with veins of a mixture of granular epidote, magnetite and a 
little uralite. 

In the second type of ore hornblende and magnetite are the most 
prominent components. Usually the two are uniformly intermixed, 
but in some cases the magnetite is scattered as tiny grains through the 
hornblende (see Plate V), and again it occurs as little streaks (see Plate 
IV) and lenses in the midst of a granular hornblende aggregate (see 
Plate VI, A.) As the ore becomes richer in grade the magnetite is seen 
to become more and more abundant and the hornblende naturally less 
abundant until in the richest ore of this type the mass is a fine-grained 
aggregate of magnetite grains 1 mm. and less in diameter, with here and 
there a grain of hornblende, a rare grain of epidote, an occasional grain 
of quartz and little nests of calcite. A few white sugary quartz veins 
run through the mass and there is in it a very obscure schistosity. In 
many cases where the schistosity is a little more marked than elsewhere 
the more highly emphasized structure appears to be due to magnetite 
which is much more abundant in certain layers than others—either as 
many little lenses embedded in sparse hornblende or as numerous grains 
that are scattered through the hornblende in some layers, while entirely 
absent from other layers. 

Where the ores are layered all the components are elongated in 
the same direction as the layering. This emphasizes the schistosity 
produced by the concentration of the magnetite in definite layers. The 
magnetite is in long, thin, ragged pieces, many of which are fractured, 
and in small grains which in most cases look as though they had been 
broken from the larger ones. The mass in which the magnetite is em¬ 
bedded is a very schistose matrix of uralitic hornblende, wisps of brown¬ 
ish-green biotite, and a little calcite and quartz. (Plate VI, B.) The 
quartz and some of the calcite are in veins that extend in the direction of 
the schistosity, and in the few sections studied the calcite veins are in 
the layers in which the magnetite is most thickly concentrated. Calcite 
is also scattered through the entire section, but it is more abundant and 


PLATE VI. 



(A) Photomicrograph of lean ore, Cranberry mine, Cranberry, N. C. Black 
is magnetite. All else is light-green amphibole. Ordinary light. X50. 

( B ) Photomicrograph of schistose ore from Teegarden mine, near Shell Creek, 
Carter County, Tenn. Black is magnetite and gray is green amphibole. Large white 
areas are calcite and small ones quartz. The needles are amphibole. Ordinary 
light. X25. 




56 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

in larger grains in the layers in which magnetite is also most abundant. 
In these layers uralite is not common. The mineral, however, con¬ 
stitutes the principal component of the layers between the richly mag¬ 
net itic layers. Its fibers are all elongate in the same direction. Asso¬ 
ciated with them are a few wisps of biotite and between these are little 
nests of calcite. Scattered through this aggregate are the small grains 
of magnetite already mentioned, and these are nearly always arranged 
roughly in lines. 

The biotite is the only component that does not orient itself with 
the schistosity. While most of its fibers in the hornblende lie parallel 
with the hornblende fibers, many others cross these perpendicularly 
and often extend into calcite grains. Evidently the biotite was pro¬ 
duced after the ore had attained its schistosity. 

The layers rich in magnetite are not sharply separated from those 
in which magnetite is present in small quantity only, nor are the mag¬ 
netite lenses embedded in hornblende sharply separated from the sur¬ 
rounding material. The portions rich in magnetite grade into those 
containing little of this mineral, and in many cases it is impossible to 
designate in hand specimens any definite lines between them. The 
relations of the magnetite to the hornblende suggest strongly that a 
schistose hornblende rock has been impregnated by magnetite and that 
the result is a magnetite-hornblende gneiss analogous to the impregna¬ 
tion gneisses so common in areas of old rocks. 

A third variety is a massive or slightly schistose garnet if erous ore 
that is found at different places in the veins, but more frequently near 
their borders or near pegmatite masses. (Plate VII) A slightly schis¬ 
tose phase from Smoky No. 2 opening at Cranberry is fine-grained and 
granular and in the hand specimen appears to be composed of little 
grains of magnetite and red garnet and between them a little chlorite 
or hornblende and tiny nests of calcite. The thin section shows the 
ore to be a mixture of green pyroxene, epidote, magnetite crystals and 
groups of crystals, large grains of calcite, irregular masses of pink gar¬ 
net, spicules of uralite and little nests of calcite embedded in a fine¬ 
grained mosaic of quartz and calcite. The ore has evidently been 
crushed and recrystallized with the production of garnet, epidote and 
uralite as new minerals. 

The uralite, epidote and calcite occupy areas in the slide that were 
originally occupied by pyroxene and the garnet frequently forms a wide 
border around them. With increase in the epidote there appears more 
and more calcite. The pyroxene broke into a lot of disconnected small 
areas and was changed to an aggregate of pyroxene, uralite, epidote 
and calcite. 

The garnet is in small irregular and sharp-edged grains in the quartz 
mosaic and in borders around the pyroxene and magnetite. The mag- 


PLATE VII. 



( A) Photomicrograph of garnetiferous magnetite ore from Smoky No 1, Cran¬ 
berry, N. C. c =calcite. g =garnet. h =hornblende. q =quartz. Black is mag¬ 
netite. Ordinary light. X50. 

(B) Same as A. Between crossed nicols. X50. 


58 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

netite is in large ragged masses that are often cellular and in numerous 
small crystals and irregular grains scattered indiscriminately among the 
other constituents. The large masses have a general elongation in one 
direction, imparting to the ore the slight schistosity noted in the hand 
specimen. Many of the small grains appear to have been broken from 
the larger masses. 

The three varieties of ore described all show distinct evidences of 
crushing and consequent metamorphism. The first variety is least 
affected. It is a pyroxene-magnetite aggregate that has been minutely 
fractured and in which the pyroxene has been partially uralitized. (Plate 
II, B.) The second variety exhibits a greater degree of metamorphism 
in that the pyroxene has completely disappeared and has been replaced 
by amphibole and at the same time the whole mass has be come schis¬ 
tose and possibly more magnetite has been added. (Plate VI, B.) 
The third varieties differ from the other two in the possession of garnet. 
(Plate VII.) As the garnetiferous varieties are localized in the vein it 
is probable that for the production of the garnets the addition of some 
constituent was necessary that had not been present in the original 
pyroxene-magnetite mass. 

In a fourth variety of ore an enrichment in iron has been brought 
about bv a later contribution of magnetite in the form of veins that 
cut the lean ore. These veins vary in width from a small fraction of an 
inch to several feet. With increase in their number and thickness the 
lean ore rapidly changes to a high-grade ore, the highest grade being 
that of the thicker veins. In some places these are wide enough tc 
furnish fragments that can easily be separated by hand from the run of 
the mine and saved for a special grade of the highest quality ore. The 
material of these veins is usually a mediumly coarse-grained aggregate, 
composed entirely of magnetite. The grains have average diameters 
of about a quarter of an inch though many of them are much larger 
than this. They are black and have a brilliant luster, in which respect 
they are distinctly different from titaniferous magnetite, which has the 
color and luster of steel. It is this variety of ore that was analyzed by 
Mr. Fairchild. (See page 102.) 

THE GANGUE 

The only place in the district where the ore vein can be studied 
in detail is at the Cranberry mine. Here there are immense dumps in 
which the many different kinds of rock occurring in the vein are repre¬ 
sented by excellent specimens. Moreover, on the walls of the large 
open pits the relations of the rocks to one another are well displayed. 
At no other place are more than a few square yards of the vein exposed 
to view, though at many places, especially in Carter County, Tenn., 
there are large dumps around the openings of explorations. As nothing 
was seen at any of these dumps that was essentially different from the 


PLATE VIII 



(A) 





(B) 


(A) Pegmatite (light), and ore (dark) in wall of open cut. Cranberry mine, 
Cranberry, N. C. 

( B) Younger pegmatite cutting irregularly across ore vein in Teegarden mine, 
near Shell Creek, Carter County, Tenn. 





60 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

things seen in specimens on the Cranberry dump, it was assumed that 
the veins are everywhere the same, and attention was directed mainly 
to the Cranberry occurrence. 

The vein at Cranberry comprises a plexus of rocks in the midst cf 
which occurs the commercial ore as a series of lenses, which so far as 
development has gone, appear to have no pitch. The plexus is cut by 
pegmatite and by veins of almost pure magnetite. The pegmatite 
cuts irregularly through the vein plexus twisting and turning in a com¬ 
plicated way and gradually fingering out. In some places it encloses 
lenses of ore and in others lenses of coarse, green hornblende. In places 
it cuts comparatively cleanly through the other rocks (Plate VIII, A), 
often with only cne sharp wall, rarely with both walls sharp. Usually 
the walls are indefinite—the pegmatitic material grading into gneiss, 
so that frequently there is a little seam of gneiss between the pegmatite 
and the rest of the vein matter. 

The main portion cf the vein, aside from the horses that occur in 
it and the veins of pegmatite and magnetite in it, consists of masses 
of hornblende, or of hornblende and magnetite, of hornblende and 
epidote, of epidote and magnetite, or of epidote and quartz, with occa¬ 
sional small quantities of molybdenite. 62 All are slightly schistose 
parallel to the strike of the vein, and some of them are well-defined 
gneisses. Especially is this true of the aggregates containing epidote. 

The epidote which is so abundant everywhere is apparently an 
alteration of feldspar. Some specimens show a continuous gradation 
from one mineral to the other. Others show a graphic arrangement 
of quartz and epidote identical with that exhibited by quartz and feld¬ 
spar in graphic-granite. Others show veinlets of epidote extending 
from large masses of pegmatite into adjacent rocks like the ordinary 
veins of feldspar so frequently found radiating from pegmatite masses. 
In rare cases veins of epidote and quartz pass into veins of magnetite 
along their strikes, apparently indicating that the materials of the two 
were introduced at the same time. That they were once part of the 
same intrusion is indicated also by the fact that epidote and magnetite 
are everywhere closely associated. 

The magnetite is closely associated with the pegmatite. The 
miners declare that the richest ore is always near pegmatite. (See 
Plate V.) The pegmatite and magnetite veins both cut the lean ore, 
which is the mixture of hornblende and magnetite referred to above, 
in the same way, and magnetite impregnations extend from the walls 
of the magnetite veins into the bordering rocks, causing an enrichment 
of these, and giving rise to magnetite gneisses. Moreover in many 
places magnetite forms a constituent of coarse pegmatite, exactly as 
does feldspar, quartz and hornblende. It has the same shapes as the 


“Unpublished report by S. H. Hamilton to Tenn. Geol. Survey. 




PLATE IX. 



Polished surface of pegmatite streaks in vein-filling, Ci-anberry mine. Cran¬ 
berry, N. C. The light material is feldspar and epidote, the black is hornblende, and 
the very dark gray, in the otherwise black rreas, is magnetite. Small lenses of horn¬ 
blende and magnetite are in the lower part of the figure, and just above them is epidote- 
hornblende gneiss. The streak through the center is a vein of quartz. (Natural 
size). 



MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


62 


other components and the individual grains, when not aggregated, are 
of the same sizes as the grains of quartz, hornblende and feldspar. More 
frequently, however, the magnetite forms groups, either alone or with 
hornblende, and these constitute lenses in the pegmatite. There is a 
strong tendency for the hornblende and magnetite to occur together. 
They appear to be among the last components to separate, and often 
they occur in great masses forming the lean ore deposits. It is probable 
that the magnetite separated in twc stages, of which one was contem¬ 
poraneous, or nearly so, with the great mass of the hornblende, and the 
other was distinctly later. Where the two minerals occur together in 
the lenses the hornblende is apt to occur on their borders with the mag¬ 
netite in their centers, and where arms extend into the surrounding 
quartz-feldspar mass the main portions of the lenses may be composed 
of magnetite or a mixture of magnetite and hornblende, while the ex¬ 
tensions consist entirely of hornblende. 

t/ 

PEGMATITE 

The pegmatite in the vein mass contains very little quartz. In 
some cases it is nearly all feldspar and in others nearly all hornblende 
or hornblende and magnetite. (Plate IX.) The fresh feldspar is very 
light pink. Near its borders, however, and wherever it is in contact 
with hornblende it has become epidotized, so that in places it is composed 
mainly of light green epidote and dark green hornblende, or a distinct 
gneiss composed of the same two minerals. (See Plate IV.) Where the 
pegmatite has been sheared without epidotization its feldspar is crushed 
to a sugary mass that is saturated with quartz. The crushed material 
forms layers from one-quarter to one inch in thickness, separated by 
very thin layers of hornblende along which the rock breaks easily. 
Evidently some of the gneiss in the vein is crushed pegmatite. 

In thin section under the microscope all of the pegmatites are more 
or less completely metamorphosed augite syenite varieties, that have 
been subjected to deformation processes. Their plagioclases, which are 
oligoclase and andesine, are shattered and cracked, and their twinning 
lamellae are gently curved or are bent into sharp angles at cracks which 
cross them. Throughout the feldspar epidote particles are common. 
(Plate X, A.) They appear in individual crystals or in groups of grains, 
but the mineral is most abundant near the contacts of the feldspar 
with hornblende or magnetite. At such contacts the feldspar is entirely 
replaced by epidote, and this is also the case in feldspar which has been 
broken into small fragments. Between the feldspar grains is a mosaic 
of quartz and fresh, untwinned feldspar, with an occasional grain of 
microcline and often grains of epidote. The consitutents of the mosaic 
frequently possess a parallel elongation. Here and there are areas in 
which a few large quartz grains are observable. These perhaps are the 
remnants of original quartz components of the pegmatite, since they are 


PLATE X 



(A) Photomicrograph of epidotized pegmatite in vein-filling, Cranberry mine, 
Cranberry, N. C. The darker gray masses are epidotized plagioclase fragments and 
the light gray ones granular quartz. The background represents voids. Ordinary 
light. X30. 

( B ) Photomicrograph of pyroxene-magnetite pegmatite, Cranberry mine 
Cranberry, N. C. E =epidote. EF =epidotized feldspar. H =uralitic amphibole, 
P =pale green amphibole with pyroxene nuclei. Ordinary light. X30. 



64 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


always divided into differently oriented sectors which show wavy ex¬ 
tinctions, while the smaller components of the mosaic are homogeneous 
throughout and extinguish sharply. In some places, more particularly 
in the triangular patches of mosaic between several neighboring feld¬ 
spars, are small masses of calcite. Since these show comparatively few 
twinning bars they are inferred to be secondary. 

The hornblende, which is present in nearly all specimens of the 
pegmatite that have been seen, is apparently all secondary. It occurs 
in large compact masses that are partial pseudomorphs of pyroxene 
and in plates, fibers and acicular crystals, either forming groups or oc¬ 
curring as individuals scattered through portions of the quartz-mosaic. 
Within the large compact masses there are often remnants of a partially 
uralitized pyroxene which is slightly pleochroic in yellowish green tints. 
(Plate X, B.) This is surrounded by a zone of compact strongly pleo¬ 
chroic uralite, and around this is a border of spicules of the same uralite. 
Many of the pyroxene remnants, like the feldspars, are fractured, and 
into the fracture cracks quartz or quartz and epidote have been forced. 
The compact hornblende which is not demonstrably derived from 
pyroxene is in large crystals that have the sieve structure characteristic 
of minerals of metamorphic origin. In them are numerous quartz and 
epidote grains and occasionally little nests of calcite. Scattered through 
the hornblende in several sections are the small regularly arranged platy 
inclusions characteristic of diallage in gabbros. The greater part of the 
hornblende, however, is a mass of small crystals and fibers intermingled 
with small quartz grains, a few tiny grains of epidote, and little nests 
of calcite. 


GNEISSES 

The gneisses that constitute such a large proportion of the vein- 
matter are for the most part medium-grained schistose aggregates of 
epidotized feldspar, hornblende and a little quartz (Plate IV), in which 
the pencil structure is prominent, or of fresh feldspar, quartz and mag¬ 
netite. There is no reason to suppose that the magnetite does not 
bear the same relation to the other components as does the hornblende, 
or as does any femic mineral in any other gneiss. Most of the gneisses 
in the Cranberry vein-mass (exclusive of that forming “horses”) are 
believed to be igneous rocks closely related to the pegmatite, and their 
structure is thought to be the result of crushing and recrystallization 
under movement in the plane of the vein. 

The sections of all the gneisses of this kind that have been examined 
show the same features. In one place, where the gneiss grades into peg¬ 
matite, the gneiss contains distinct layers of lean ore, consisting of horn¬ 
blende and magnetite, that apparently bevel the foliation of the gneiss 
at a low angle. In the hand specimen the lean ore-layers and the gneiss 


PLATE XI. 





( B) 


( A ) Photomicrograph of epidote-hornblende gneiss. Vein-fllling, 
mine, Cranberry, N. C. G =garnet. H =hornblende. C =calcite. 
clase. E =epidote. Q = quartz. Urainary light. X50. 

( B) Same as A. Between crossed nicols. X50. 


Cranberry 
P =plagio- 



6G 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


appear to be tightly frozen, but they easily break apart revealing slicken- 
sided fracture surfaces coated with chlorite or uralite. 

Under the microscope the gneiss is seen to consist principally of 
parallel flat lenses of granular epidote and feldspar and others of uralite 
and quartz and feldspar. In addition there are a few comparatively 
large lenses of feldspar with many tiny crystals of epidote scattered 
through them. These are cut by quartz veinlets parallel to the general 
schistosity. 

Another section of epidote-hornblende gneiss grading into feldspar- 
hornblende gneiss is a mass of fragments of plagioclase, enclosing epidote 
grains, and nests of calcite in a matrix of smaller fragments of feldspar, 
quartz grains, hornblende flakes, grains of epidote and nests of calcite. 
Much of the epidote is in very small colorless granules scattered through 
feldspar, quartz and calcite indifferently; but there are also large masses 
of a yellow-green variety associated with hornblende. A few grains of 
magnetite are also present, and one of these is surrounded by leucoxene. 
Most of the plagioclase is characterized by bent twinning lamellae. 
(See Plate XI.) 

Other gneisses are clearly injection gneisses. (See Plate IX) 
Thin layers of pegmatite are interlaminated with thin layers of horn¬ 
blende and magnetite. The pegmatite appears to have intruded a 
schistose hornblende in little veins and stringers, all running in the same 
general direction, but in a few places crossing little streaks of the horn- 
blendite and surrounding little islands of the rock. Some of the layers 
of pegmatite are very narrow (from .1 to .01 inch,) but they have a 
fashion of swelling into lenses half an inch wide, forming the well-known 
augen of augen gneisses. Many of the narrower streaks and the smaller 
lenses are now composed entirely of epidote. 

All the gneisses studied are directly or indirectly the result of defor¬ 
mation, except, perhaps, the “augen gneiss” which may have been the 
result of intrusions into a schist. But even in this the intruding mass 
has suffered crushing, since the tiny streaks of feldspar and epidote 
that now represent the pegmatite are composed of little epidote crystals 
mingled with the debris of shattered plagioclase. (See Plate XI, B.) 

RELATIONS OF THE ROCKS IN THE VEIN-MASS 

The relation of the pegmatite to the coarse hornblende masses in 
the vein is difficult to determine. In some specimens the pegmatite 
appears to be older than the hornblende rock, but in most places it is 
later. It intrudes the hornblende in distinct dikes and little stringers 
all running in the same direction forming a gneiss (Plate IX), and it 
also crosses little streaks of the hornblende and surrounds little islands 
of this mineral. The gross aspect of specimens showing these relations 
is that of an injection gneiss. 


SILICEOUS MAGNETITES 


67 


In the ease of the epidote-hornblende-magnetite gneisses the horn¬ 
blende and magnetite appear to be contemporaneous, but distinct, and 
definite layers of magnetite and hornblende cut across the schistosity 
of the gneiss in such a way as to leave no doubt that the material of the 
gneiss is the older. Moreover veinlets of magnetite cut the gneiss as 
do also little veins of quartz. In other places almost pure magnetite 
sends tongues into epidotized pegmatite. In most places there is a little 
layer of hornblende between the epidote and the magnetite in the tongues 
and not infrequently the magnetite plays out and is replaced by horn¬ 
blende. 

Much of the gneiss is unquestionably a mashed and sheared peg¬ 
matite in which the feldspar has been altered to epidote and the augite 
to hornblende. Some of this originally contained magnetite. The horn¬ 
blende and magnetite that cuts this gneiss is plainly a later intrusion. 

Thus some of the pegmatite is later than some of the hornblende- 
magnetite aggregates that constitute much of the lean ore and some of 
the hornblende and magnetite is later than some of the sheared peg¬ 
matite, now forming gneisses. 

The relative ages of the less gneissoid pegmatite and the less gneiss- 
oid magnetite and hornblende is not known. Probably they were con¬ 
temporaneous in the sense that they were the result of a continuous 
intrusive process. 

AGE 

The most striking feature of thin sections made from ore and gangue 
is the granulation of the quartz and the feldspar. In many, too, the 
magnetite grains are broken and their parts separated. The amount of 
crushing suffered by the constituents of the vein is even greater than 
that suffered by the surrounding granite, if one may judge from the 
appearance of the thin sections. This is directly in opposition to 
Keith’s 53 view that the deposit was made after the deformation of the 
region, and long after the enclosing granite had been made schistose, 
because the minerals composing the ore and gangue “are only slightly 
crushed and rearranged, although they are the same varieties which in 
adjacent formations show the greatest metamorphism.” 

Keith did not have the advantage of a study of thin sections of 
the ore and gangue. Because he found no evidence of crushing in the 
vein-filling, he concluded that the vein could not have been earlier than 
the beginning of Mesozoic time. 

The microscopic study of the ore and gangue shows that the vein¬ 
filling suffered a great amount of metamorphism. It was sheared, 
crushed and nearly all of its original components were altered. Conse¬ 
quently it must have been involved in the deformations that took place 


s^Keith, Arthur, U. S. Geol. Surv. Geol. Atlas, U. S., Cranberry folio (No. 90), p. 8, 1903. 




68 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

before the beginning of Mesozoic time. Moreover, as there are no veins 
of a similar character in the Cambrian beds of the district, nor any peg¬ 
matites in these beds, so far as is now known, the vein is probably pre- 
Cambrian in age. 

ORIGIN 

Since the Cranberry vein was believed by Keith 54 to have originated 
in Mesozoic time, he was compelled to find a source for its material 
that was effective in Mesozoic time. This he believed to be at hand 
in the Bakersville gabbro to which he had assigned a Mesozoic age, 
because it seemed to exhibit no schistosity or other deformational 
effects. It seemed to him probable that the vein replaced an igneous, 
diabase-like mass that intruded granite, and that the ore was “due to 
alterations begun by the gabbro intrusions.” However, since there are 
no “later intrusions” of gabbro or diabase in Ashe County where mag¬ 
netites similar the the Cranberry magnetites occurs, it is unlikely that 
the ore in this region can have been produced by the process outlined. 
Mr. Keith thought that the iron in Ashe County may have been dissolved 
from the Roan gneiss through which the mineralizing solutions must 
have passed in more than one epoch. 

Since the study of thin sections of the country rock, the Bakersville 
gabbro and the vein-filling shows crushing in all cases, there appears to be 
no compelling reason for correlating the vein with the gabbro, nor is there 
any reason to assume that the vein was produced by the alteration of 
some pre-existing dike. It appears much more probable that the vein 
originated in the same way as did the numerous pegmatite veins of the 
district, i. e., that it was forced into the country rocks by the same 
agencies that caused the intrusion of pegmatites elsewhere. 

The relations of pegmatite, gneiss, hornblendite and magnetite in 
the vein suggest that they are all parts of a contemporaneous intrusion 
that took place before the general deformation of the mountain region 
was concluded. The intrusion was apparently a magnetitic pyroxene 
pegmatite, followed later by an intrusion of pyroxene-magnetite and 
finally by one of magnetite. According to this view the magnetites of 
North Carolina originated in pretty much the same way as those of New 
Jersey. In the northern State the iron ore was brought up by pegma¬ 
tites that were differentiates of some igneous mass beneath. In both 
States intrusions of less siliceous ferriferous magmas, producing pyroxene 
pegmatite and magnetite, followed more siliceous magmas producing 
quartzose pegmatites and were themselves followed in the last stages of 
the intrusion by magmas or solutions that deposited pyroxene and mag¬ 
netite and finally mainly magnetite. The source of the liquids is not 
known, but they might well have come from the magmas that furnished 
the gabbros, diorites and other basic sills, etc., in the Roan gneiss series, 


sMdem., p. 8. 




SILICEOUS MAGNETITES 


69 


which may not have antedated the Cranberry granite by any great 
length of time, or they may have come from the magmas that later rose 
as Algonkian volcanics and brought with them iron compounds to form 
the hematite-magnetite ores (page 244), of Buck Mountain, Carter 
County, Tenn. According to this view the magnetites in the Mountain 
district belong with the injected pneumotectic magmatic deposits, re¬ 
cently defined by Lindgren. 55 

UTILIZATION 

The availability of the magnetite deposits depends upon their 
ability to furnish to the furnace at a reasonable cost a large quantity 
of ore with an iron content of 40 per cent, or more. There are many 
'deposits that will supply small quantities of such ore, but, as will be 
noted by reference to the description of the ore veins (see page 48), 
the expense of selecting it in the mine would be considerable. So far 
as is now known there are no deposits in western North Carolina or 
East Tennessee that could be made to yield a continuous supply of 
such ore to even a small furnace. Most of the ore is of lower grade than 
this and must be concentrated to be of commercial value. The Cran¬ 
berry mine is now sending to the furnace ore that is of comparatively 
low grade, but even this is hand cobbed to some extent. During the 
last three months before the mine was closed the direct shipments from 
the mine to the furnace averaged: 


Iron Phosphorus 

September. 40.14 .0117 

October . 40.70 .0103 

November. 38.85 .0097 


and the average of the shipments in May, June and July for the same 
year (1920) was: iron, 38.72 per cent and phosphorus, .0112 per cent. 

These shipments were made from selected headings in the mine 
and represent what is believed to be the best ore that can be obtained 
in large tonnages. It is not probable that any other deposit in the 
district will afford as much crude shipping ore as that at Cranberry. 
Most of the ore in the district will have to be concentrated before it 
becomes available, and the method of concentration employed must be 
such as to increase the content of its iron while avoiding the concentration 
of phosphorus. The mining of the ore will justify itself financially only 
if the resulting concentrate will make a very low phosphorus pig-iron. 
The Cranberry iron is guaranteed not to exceed 0.035 per cent in phos¬ 
phorus, consequently the ore from which it is made must not contain 
an average of more than about 0.02 per cent of this element. 

Until October, 1919, the ore was cobbed and then concentrated mag¬ 
netically with the result that much of the ore too lean to be shipped 
direct was made available for use. The mill was closed at the end of 

“Lindgren, Waldemar, A suggestion for the terminology of certain mineral deposits: 
Econ. Geol., vol. 17, p. 292, 1922. 






70 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

October, 1919. During the last four months of its operation 9,941 tons 
were shipped. This was classified as cobbed ore, concentrates and fine 
concentrates, the latter including five-eighths inch material and dust. 
The proportions of each and the composition of each class were as fol¬ 
lows : 

Proportions and quality of different classes of ore shipped from the Cranberry mine in the 

summer of 1919. 





Tons 

Percent 

Fe 

P 

Crusher ore. 




100.0 

33.28 

.0275 

Cobbed ore. 



1712 

17.2 

48.00 

.0095 

Tails 





28.29 


Coarse concentrates. 

*■ 






Heads. 





44.90 

.0104 

Tails . 





25.07 


Coarse cone, retreats. 







Heads. 





42.60 

.0113 

Tails 





14.57 


Finf*r nnnopntrfltps . 

> 

7276 

73.25 



Heads. 



45.15 

.0111 

Tails. . . 





18.41 


Finer cone, retreats. 







Heads. 





40.76 

.0134 

Tails. ... 

.J 




15.89 


Fine concentrates. 







5-8 inch ore. 







Heads. 





57.91 

.0079 

Tails. 



953 

9.6 

17.27 


Dust 





Heads. 





60.56 

.0073 

Tails. 





19.30 



In 1913 a test was made to determine the quantities of the various 
classes of ore produced by the mill, using 20 cars of crude ore taken 
from the mine and the storage bin. The aggregate weight of crude ore 
used was 120,352 lbs. and the weights and proportions of the ore pro¬ 
duced were: 

Proportions of different grades of concentrates produced from ore of Cranberry mine in 1913 



Pounds 

Perce 

nt 

Cobbed heads. 

18.450 

15. 

3 

Coarse concentrates. 

23,895 

19. 

8 

Finer concentrates. 

14,700 

12 

.2 

Fine concentrates. 

11,600 

9. 

6 

Total. 

. . 68,645 

56. 

9 


These results show clearly that in the case of the Cranberry ore, 
and presumably that of the other magnetite deposits in the Mountain 
district it is possible, by magnetic methods, to secure a product with a 
higher content of iron than that in the crude ore without at the same 
time increasing the phosphorus. Indeed, the results show a dimunition 














































SILICEOUS MAGNETITES 


71 


of the phosphorus as iron increases, due no doubt to the fact that most 
of the phosphorus is in the mineral apatite, which is more closely asso¬ 
ciated with the hornblende in the ore than with the magnetite and con¬ 
sequently accompanies it into the tails. The magnetic process is satis¬ 
factory in producing a merchantable ore, its success commercially de¬ 
pends upon costs. The Cranberry mill was shut down, not because it 
could not produce a satisfactory concentrate from the ore at hand, but 
because costs were too high. 

The runs made in 1913 showed that it required two tons of crude 
ore, then mined, to make one ton of concentrate containing about 46 
per cent, of iron; but there is no record of the iron content of the ore 
fed to the mill. The commercial success of the magnetic concentration 
method as applied to the mountain magnetites will depend upon the 
availability of a quantity of crude ore that will have a sufficiently high 
content of iron to yield a large enough product of satisfactory grade to 
pay costs of mining and concentration. Naturally the lower the grade 
of ore that can be utilized for the production of such a concentrate the 
greater will be the quantity of ore available for this purpose, and the 
larger will be the reserves for future use. 

With the idea of working out a cheap method for the concentration 
of the mountain ores and of determining the lowest grade ore that would 
be profitable to mine for concentration by the method that might be 
developed, samples were taken from the Cranberry mine slopes and sub¬ 
mitted to the Bureau of Mines Experiment Station at Minneapolis for 
study. 

One series of low grade ores included 5 samples taken from the walls 
of the Cranberry mine at the points indicated by the sample numbers 
(see Plate XVI.) These were analyzed for total and magnetic iron and 
phosphorus and then subjected to the tests indicated below. One set 
of tests consisted in crushing to quarter-inch size and subjecting to the 
influence of magnets of gradually increasing strengths. The results are 
shown under the heading “Dry cobbing tests." A second set of tests 
consisted in fine grinding to pass sieves of 14, 28, 48 and 100 meshes 
and concentrating under water with magnets sufficiently strong in all 
cases to prevent loss of any iron in the tailings. 56 The results of this 
are shown under the heading “Wet magnetic concentration." Only the 
results of the study of the sample 5-L are given; since the results of the 
treatment of all samples were similar, except of course, that the per¬ 
centage yields of high-grade concentrates were less in the case of crude 
ore containing smaller quantities of iron. Sample 5-L represents about 
the lowest grade ore that might be concentrated with profit under very 
favorable conditions with respect to costs and the selling price of pig 
iron. 

58 For detailed discussion of the method employed in making these tests, see: Davis, 
E. W., Magnetic concentration of iron ore: Minnesota School of Mines Experiment Station 
Bull. 9, 1921. 



72 


MAGNETIC IKON ORES OF EAST TENN. AND WESTERN N. C. 


Composition of samples of low grade ore from the Cranberry mine, N. (., on which mag 
netic concentration tests were made by the U. S. Bureau of Mines Experiment 

Station, at Minneapolis, Minn. 


Sample No. 

Total Soluble iron 

Percent 

Magnetic iron 
Percent 

Total phosphorus 
Percent 

Lot 5 G 

15.52 

10.47 

.0362 

“ 5 H 

13.84 

7.35 

.0223 

“ 5 I 

15.11 

9.81 

.0303 

“ 5 K 

21.51 

14.54 

.0180 

“ 5 L 

25.47 

22.03 

.0575 



Rresults of concentration tests on 

Sample 5— L. 



Number of test 

Yield 

Dry cobbing tests 

Concentrates 

Composition 

Fe P 

Yield 

Tailings 

Composition 

Fe P 


Percent 

Percent 

Percent 

Percent 

Percent 

Percent 

First. 

29.57 

59.65 

0.0076 

70.43 

11.11 

0.0785 

Second. 

36.85 

56.82 

0.0125 

63.15 

7.17 

0.0838 

Third. 

41.91 

51.83 

0.0198 

58.09 

6.44 

0.0847 

Fourth. 

58.95 

39.87 

0.0326 

41.05 

4.78 

0.0932 


Size 

Yield 

Wet magnetic concentration 

Concentrates 

Composition 

Fe P Yield 

Tailings 

Composition 

Fe P 

Mesh 

Percent 

Percent 

Percent 

Percent 

Percent 

Percent 

14. 

39.38 

57.87 

0.0107 

60.62 

4.27 


28. 

34.07 

64.91 

0.0058 

75.93 

4.95 


48. 

33.95 

67.91 

0.0038 

66.05 

3.52 


100. 

31.89 

70.46 

0.0020 

68.11 

4.27 



After considering the results of the tests made on all the samples 
Messrs. E. W. Davis and H. H. Wade of the Bureau comment as fol¬ 
lows : 

“The results of these tests show that by dry cobbing at 1-4 inch, in all cases a 
concentrate can be produced assaying between 50% and 60% in iron and between 
.0178% and .0048% in phosphorus. In order to secure these results it was necessary 
to discard a tailing assaying from 3% to 7% magnetic iron. As the assay of the feed 
was low, a 7% magnetic iron tailing produced, in some cases, an excessive iron loss. 
Under ordinary conditions, however, these would be considered satisfactory results. 

“In the finer grinding tests followed by wet magnetic concentration, the tailing 
produced contained in all cases practically no magnetic iron. This is due to the nature 
of the machine used in making these tests. 

“The assay of the concentrate made at—100 mesh was in all cases between 65% 
and 70% iron and about .002% phosphorus. This is, of course, a very high grade 
concentrate, but in order to produce it from Lot 5G, for example, it would be necessary 
to mine, coarse crush and possibly cobb 6 tons of ore, fine grind to—100 mesh and 
concentrate possibly 3 tons of ore, and sinter one ton of ore in order to produce one ton 














SILICEOUS MAGNETITES 


73 


o! finished product. From an economic point of view this is undoubtedly out of the 
question, but it is interesting to notice that from an ore assaying only 7% magnetic 
iron a very high grade, low phosphorus concentrate can be produced. 

“In most of these samples the magnetic iron assay was considerably lower than 
the soluble iron assay. This is due to the fact that some of the soluble iron exists in 
the ore in a non-magnetic state and therefore cannot be recovered by magnetic concen¬ 
tration methods. It is not possible by means of chemical analysis to determine the 
magnetic characteristics of an ore, and since the relation between the soluble iron and 
magnetic iron varies so considerably in the mountain ores, it is advisable to investigate 
the deposits with reference to their content of magnetic iron as well as of total iron.” 

In view of the results obtained in the experiments on the series of 
samples representing an average of the Cranberry vein, a second series 
of samples was taken to represent the average of the ore that might 
readily be taken from the vein without including the leaner portions of 
the vein-filling. The samples were taken from the headings that were 
being worked at the time the mine was closed. One represented the 
ore that is sent direct to the furnace without concentration, one is 
good milling ore and two represent average milling ore. The direct ore 
came from 5-Q and 5-R, the good milling ore from 5-P and the average 
milling ore from 5-K, 5-L, 5-M and 5-0. (See mine plat, Plate XVI.) 

These samples were also sent to the Experiment Station of the U. 
S. Bureau of Mines at Minneapolis, Minn., where they were crushed 
and passed through the experimental magnetic concentrator with the 
results outlined in the following few pages. 

Analyses of the samples gave: 

Composition of samples of crude ore from Cranberry mine. Cranberry, N. C., on which 
magnetic concentration tests were made by the U. S. Bureau of Mines Experiment 

Station at Minneapolis, Minn. 


Sample No. 

Percent 
soluble iron 

Percent 
total iron 

Percent 

iron in magnetite 

Percent 

total phosphorus 

1 

33.25 

4- 

i— > 

o 

31.02 

0.009 

2 

28.45 

37.12 

26.09 

0.012 

3 

24.41 

30.92 

21.42 

0.013 

4 

27.67 

34.50 

22.96 

0.016 


The ore was first crushed to quarter-inch size, and a portion was 
put over a dry cobber at various magnetic field strengths, the field 
strength being decreased with each succeeding test. Other portions 
of each sample were crushed to —14, —28, —48, and —100 mesh and 
wet concentration tests were made at each size in a magnetic tube con¬ 
centrator. In these wet tests the magnet used was sufficiently strong 
to prevent the loss of any large amount of magnetic iron in the tailing. 
The results of the tests are tabulated below. 


74 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Results of concentration tests on 

samples of ore 

from Cran 

berry mine . 




Dry cobbing tests. 




Sample No. 1 

Number 


Concentrates 


Tailings 

Composition 

of test 

Yield 

Composition 

Yield 

Iron in 




Fe 

P 


magnetite 

Perrent 


Percent 

Percent 

Percent 

Percent 

Percent 

Total Fe . .41.20 

First 

89.74 

43.88 

0.008 

10.26 

1.69 

“ P ... 0.009 

Second 

77.77 

47.60 

0.008 

22.23 

1.74 


Third 

61.97 

53.24 

0.007 

38.03 

5.36 

Sample No. 2 
Composition 

Fourth 

50.00 

57.17 

0.007 

50.00 

9.85 

Percent 







Total Fe . .37.12 

First 

82.83 

41.12 

0.009 

17.17 

2.60 

“ P . . . 0.012 

Second 

69.10 

45.44 

0.008 

30.90 

2.83 


Third 

54.94 

50.87 

0.007 

45.06 

4.92 

Sample No. 3 
Composition 

Fourth 

42.93 

54.76 

0.007 

57.07 

9.07 

Percent 







Total Fe ..30.92 

First 

71.70 

37.47 

0.011 

28.30 

3.05 

“ P ... 0.013 

Second 

52.45 

44.72 

0.011 

47.55 

3.44 


Third 

36.60 

54.20 

0.010 

63.40 

5.17 

Sample No. I 
Composition 

Fourth 

28.30 

58.44 

0.009 

71.70 

8.18 

Percent 







Total Fe ..34.50 

First 

75.37 

39.73 

0.012 

24.63 

1.76 

“ P . .. 0.016 

Second 

59.83 

44.71 

0.011 

40.17 

3.31 


Third 

43.11 

51.92 

0.008 

56.89 

5.69 


Fourth 

31.97 

56.31 

0.007 

68.03 

9.48 


Wet magnetic concentration tests. 



Sample No. 1 



Concentrates 


Tul 

ings 

Composition 

Si/.e 

Yield 

Composition 

Yield 

Iron in 




Fe 

P 


magnetite 

Percent 

M (“••// 

Percent 

Percent 

Percent 

Percent 

Percent 

Total Fe . . 41.20 

—100 

43.26 

71.49 

0.005 

56.74 

4.19 


—48 

45.39 

69.10 

0.005 

54.61 

4.03 

“ P ... 0.009 

—28 

52.05 

62.86 

0.006 

47.95 

3.58 

Sample No. 2 
Composition 

—14 

Size 

62.55 

55.63 

0.006 

37.45 

3.50 

Percent 

Meal) 






Total Fe ..37.12 

—100 

36.88 

71.44 

0.004 

63.12 

3.59 


—48 

39.79 

68.03 

0.004 

60.21 

2.89 

“ P ... 0.012 

—28 

45.04 

62.10 

0.005 

54.96 

3.50 


—14 

61.53 

50.38 

0.006 

38.47 

3.35 

Sample No. 8 
Composition 

Size 






Percent 

Mesh 






Total Fe . . 30.92 

—100 

29.83 

71.14 

0.004 

70.07 

4.49 


—48 

32.29 

67.42 

0.005 

67.71 

4.26 

“ P . . . 0.013 

—28 

35.29 

61.79 

0.005 

64.71 

5.02 


— 14 

45.13 

51.90 

0.005 

54.87 

4.87 

Sample No. 4 
Composition 

Size 






Pen-cut. 

Mesh 






Total Fe ..34.50 

—100 

30.37 

70.99 

0.004 

69.63 

8.91 


—48 

32.69 

68.18 

0.005 

67.31 

8.14 

“ P ... 0.016 

—28 

37.29 

61.95 

0.006 

62.71 

8.37 


— 14 

57.01 

47.03 

0.010 

42.99 

8.45 


SILICEOUS MAGNETITES 


75 


In the tables the only iron reported as being present in the tailings 
is that in magnetite. There is present in addition, however, also the 
iron that is in the silicates which are not carried to the magnets. The 
iron in the magnetite is significant as indicating the efficiency of the 
process used and for this reason is recorded. In the concentrates the 
iron in the silicates that are caught by the magnets as well as that in 
magnetite is of value to the furnace man, so that the figures given in 
the column showing the percentage of iron in the concentrate are for 
total iron. 

The results of the dry cobbing tests show that each of the four 
samples when crushed to quarter-inch size produces a concentrate assay¬ 
ing between 50 and 00 per cent of total iron, and 0.007 to 0.010 per cent 
of phosphorus. However, the amount of the concentrate varies with 
the different lots. From lot No. 3, in the fourth test 28.30 per cent of 
the crude ore is recovered as a concentrate assaying 58.44 per cent total 
iron, whereas from lot No. 1, 50.00 per cent of the crude ore is recovered 
as a concentrate assaying 57.17 per cent total iron. The reason for 
this variation in recovery, according to Messrs. E. W. Davis and H. H. 
Wade of the Experiment Station, is the difference in (1) the amounts of 
iron in the original samples, and (2) the difference in their structure. 
The ore and gangue are more intimately associated in lot No. 3 than in 
lot No. 1. Cobbing at coarser sizes than quarter-inch was impossible 
on account of the small size of the samples. 

In the wet concentration tests, a concentrate assaying 70 to 71 
per cent of total iron and between 0.004 and 0.005 per cent of phos¬ 
phorus was obtained in all four lots at —100 mesh. The average ratio 
of concentration for the lots is about 3 tons into 1. Coarser grinding 
and concentrating lowers the total iron content by from 2 per cent to 
4 per cent but increases the yield, slightly improving the ratio of con¬ 
centration. 

Messrs. Davis and Wade remark 1 that “as a result of these tests it 
would seem that a satisfactory method of concentration could be pro¬ 
vided by cobbing out 30 or 40 per cent of the weight of the crude ore 
assaying under 5 per cent, magnetic iron and then grinding the cobber 
concentrate to —48 mesh preliminary to wet magnetic concentration. 
This would mean that it would be necessary to mine, crush, and cobb 
three tons of ore, thus producing 1.2 tons of tailing to be discarded and 
1.8 tons of cobber concentrate to be crushed to —48 mesh and concen¬ 
trated wet. About one ton of concentrate would then be produced 
assaying about 63 per cent iron and 0.006 per cent phosphorus. 

By carefid sizing and cobbing, a dry method of concentration could 
be provided which would produce a concentrate assaying about 56 per 
cent iron and 0.01 per cent phosphorus. No fine grinding or sintering 


Un report on Ore No. 582 dated Dec. 12, 1921. 






76 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

plant would be required and the cost of operating and constructing a 
plant for this method of operation would be about one-half of that 
employing wet concentration. It is doubtful if a concentrate much 
higher than 56 per cent, iron could be made without producing a high 
tailing loss.” 

Their conclusions are essentially as follows: 

(1) By dry concentration methods a concentrate assaying about 
56 per cent of iron and 0.01 per cent of phosphorus can be made with 
a ratio of concentrates of about 2.5 tons into 1. 

(2) By wet concentration methods a concentrate can be made 
assaying as high in iron as desired. However, for higher assaying con¬ 
centrates, the grinding must be finer and the more expensive will be 
the process. 

(3) Any grade concentrate can be made, but in order to determine 
the grade that would be most profitable to produce, a careful economic 
study of mining and milling costs is necessary. 

It will be learned from the results of the tests on samples of magnetic 
ores ranging from 13.84 to 41.20 per cent of total iron and 7.35 to 31.02 
per cent of iron in magnetite that there is no difficulty in producing 
concentrates sufficiently high in iron to be merchantable. It is prob¬ 
able, however, that no ore would be profitable to work unless it contains 
at least 22 per cent of iron in magnetite and can be produced at a low 
cost for mining. At most of the deposits in the Mountain district ores 
of this grade can be produced, but at only a few of them can they be 
produced on a scale large enough to keep mining costs low. In esti¬ 
mating the value of a deposit it is necessary, therefore, not only to de¬ 
termine the percentage of magnetite present, but also to determine the 
quantity of ore present and the cost of mining it. 

RESERVES 

Because of the superficial character of nearly all the explorations 
of the magnetite deposits in the Mountain district there are no data on 
which an estimate of the reserves of magnetic ore in the district can be 
based. Most of the explorations have been confined merely to the un¬ 
covering of the ore. In Ashe County, N. C., a few tunnels and shafts 
have been excavated, but none of them reach more than a few score feet 
underground. In Carter County, Tenn., a number of openings have 
been made in the western extension of the Cranberry vein and at some 
places considerable ore has been taken out. But here, also, the depths 
of the openings are slight. Only at the Cranberry mine has any ex¬ 
tensive opening been made. Nearly all the excavation has been con¬ 
fined to the ground above the floor of the tunnel which enters the base 
of the hill at the level of the railroad track. There has been little ex- 


SILICEOUS MAGNETITES 


77 

ploration ahead of mining and there is therefore almost nothing known 
of the ore conditions beyond the walls of the present mine opening. 

It is known, of course, that there are numerous lenses of ore in the 
schists and gneisses of the district and that they occur in belts, but 
little is known about the sizes of the lenses, or about their distribution 
in the belts. In some places the lenses are so crowded that the series 
becomes practically a continuous uniformly thick vein of ore. In others 
they are some distance apart and are separated by stretches of vein 
containing little ore, or by pinches of the wall rocks leaving only a nar¬ 
row width of vein between. 

Another difficulty in attempting to estimate the reserves arises from 
the fact that it is impossible to determine the ratio between the magnetite 
and gangue in the deposits without chemical or physical analyses, and 
these are valueless unless the samples analyzed are so selected as to 
show the distribution of ore and gangue. In no case have such samples 
been available. Moreover, it is not yet known what constitutes an 
available ore. If an available ore is only that material which contains at 
least 39 per cent, of iron, the quantity that might be obtained from the 
mountain deposits is so small as to be negligible, as only few deposits 
would yield enough of such ore as to be worthy of consideration by fur¬ 
nace operators. On the other hand, if lower grade ores can be concen¬ 
trated to yield a comparatively high grade product the available reserves 
are increased as the grade of crude ore that can be concentrated to a 
merchantable product becomes lower and lower. The limit will be 
reached when the grade of crude ore becomes so low that it will not 
yield a merchantable product in sufficient quantity to pay the cost of 
mining and concentration. What this limit is we do not yet know. 

Since it is impossible to estimate the reserves on the strength of 
the data now at our disposal, it is necessary to base any estimate on 
assumptions. This kind of an estimate is justifiable if it is clearly un¬ 
derstood that it is based on assumptions and not upon known facts and 
that it is offered merely as a quantity that should be modified to accord 
with conditions as new facts are developed by explorations and milling 
tests. 

In 1892, at the Cranberry mine, according to Nitze 57 , an ore body 
had been opened and explored through a length of 875 feet, a breadth 
of 300 feet, and an average depth of 165 feet, representing approximately 
1,600,000 yards of material. “Assuming that the gangue and ore are 
equally divided, half-and-half, and taking the specific gravity of magne¬ 
tite at 5.1 and of the gangue at 3, this volume would contain 4,800,000 
tons (gross) of ore material, of which over 3,000,000 tons are pure ore.” 
Since 1884 about 1,360,000 tons of ore have been shipped, though nearly 
the entire slice referred to by Nitze has been mined except those por- 


57 Op. cit., p. 170. 



78 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


lions which were too lean to warrant the expense of removal and con¬ 
centration, and an additional quantity has been taken from the north¬ 
west portion of the mine which had not been developed at the time of 
Nitze’s visit. It is evident that Nitze’s estimate of 50 per cent ore in 
the slice was too large. It is now clear that the slice, the dimensions 
of which are given by Nitze, was not all occupied by a single lens of 
uniform thickness throughout, and that a fair estimate of the ore in the 
mine was impossible because of insufficient exploratory work. The same 
difficulties lie in the way of making a fair estimate today. 

An inspection of the mine plat, (Plate XVI), will show that the ore 
has come from lenses separated from one another partly by pinches in 
the vein and partly by the narrowing of the richer portions of the vein¬ 
filling. There is no probability that the lenses terminate suddenly 
with depth. If the source of the ore was, as is supposed, a subterranean 
magma is is probable that the deposits extend downward for some 
distance. There should be ore below the present works, and the quan¬ 
tity should be approximately the same per unit of mass beneath the 
present workings as has been taken from the mine in those portions 
that have been worked out. If 1,500,000 tons of ore have been removed 
from the present workings which measure about 1,800 feet long, from a 
few feet to 200 feet wide, and about 550 feet high, and 200,000 tons 
still remain in the upper levels, in an equal vertical distance of 550 feet 
below the present bottom of the mine there is probably a similar tonnage 
(of 1,700,000 tons) in every 1,800 feet on the length of the vein. There 
is no evidence as to how far the vein extends with its present width either 
in a northwest or southeast direction, but magnetic observations made 
to the northwest indicate a number of swellings that represent lenses 
of ore. If the vein extends 1,800 feet beyond the present end of the 
mine with an average width beyond the present workings of only half 
of that in the workings, the quantity of ore that is still available above 
a depth of 550 feet below the present level is 3,000,000 tons, without 
considering that portion of the vein that extends southeast of Cranberry, 
in which there is considerable ore. In the past, however, much of the 
material taken from the mine has been rejected because too lean to pass 
as ore. Much of this might yield a good concentrate under proper 
conditions with an efficient concentrating plant. One has only to glance 
at the ballast on the Linville Valley Railroad, southeast of Cranberry, 
to realize that much good ore has heretofore been wasted. Had all the 
material removed from the mine been passed through a suitable concen¬ 
trator the yield of merchantable ore would have been much greater 
than it has been and the calculated reserve would be correspondingly 
greater. The quantity of ore that can be produced will naturally depend 
largely upon the cost of mining and concentration. In the future min¬ 
ing costs should normally increase because the ore still to be won will 
require a longer tramming than that which has already been produced 


SILICEOUS MAGNETITES 


79 


and most of it will have to be raised to the tunnel level, whereas here¬ 
tofore much of it has been dropped to this level by gravity. However, 
it is probable that with an economical concentration plant, costs will 
still be below the value of the concentrate, for in the Hibernia mine 58 
in New Jersey, where the ore is very like that at Cranberry, an ore 
containing about 30 per cent, of iron is being raised from a depth 
of 1,500 feet and concentrated, presumably at a profit. The con¬ 
centrates at the Hibernia mine in 1908 had a content of 62.80 per 
cent, of iron and 0.231 per cent, of phosphorus. As a concentrate could 
be obtained at the Cranberry mine with a much smaller content of phos¬ 
phorus than that in the Hibernia concentrate, it seems certain that a 
moderately rich Cranberry ore could stand the cost of mining from 
reasonable depths below the tunnel level. 

Northwest of the Cranberry mine on the same vein, or at any rate, 
in the same belt of veins, there are known to be several other deposits 
of good ore that are connected by lines of magnetic attraction. (See 
Plate I.) The sizes, however, of these deposits are not known. At 
the Horse Shoe, Teegarden, and Wilder mines the deposits are probably 
large enough to be worked under present conditions, but in each case 
the ore is comparatively lean. With an efficient concentrating plant 
to which the crude ore could be sent it is probable that some of the other 
deposits might be exploited. Such a plant, if built, should be situated 
at Roan Mountain or Shell Creek, Tenn., where all of the ore that might 
be raised between Cranberry and the Teegarden mine could be sent to 
it by a down-grade haul on the railroad. A plant at Roan Mountain 
would also be conveniently situated with reference to any ore that might 
be raised at the Peg Leg and Horse Shoe mines and in the intervening 
country. 

It is impossible to estimate the amount of crude ore that would be 
contributory to such a plant, but if the average width of those portions 
of the deposits that would be worth concentrating is 15 feet and one- 
half the length of the belt is barren, the quantity of crude ore in the 5^ 
miles between the Cranberry and Peg Leg mines is 3,000,000 tons for 
every 100 feet in depth. Since the width of the nearly pure magnetite 
exposed in the openings that have been made varies in width from 4 feet 
to 20 feet, it is probable that the crude ore would yield about 75 per 
cent, of commercial concentrate. On these assumptions 2,250,000 tons 
of concentrate are indicated for every 100 feet of depth. 

At the Wilder and the Teegarden mines, south of Shell Creek, are 
the two most promising undeveloped deposits known in the belt. At 
both places magnetic surveys (Plate XIX) were made by Mr. S. H. 
Hamilton for the Cranberry Furnace Company 59 . The results of 

ssBaylev W S Iron mines and mining in New Jersey: Final Report Series of the 
State Geologist, vol. 7, Geol. Survey of New Jersey, p. 456, 1910. 

^Unpublished manuscript report in the possession of the Tennessee Geol. Survey. 





80 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

these surveys indicate, according to Mr. Hamilton, the presence of 
150,000 tons of probable ore and 600,000 tons of possible ore, and at the 
Teegarden mine and vicinity about 250,000 tons of probable ore and 
1,000,000 tons of possible ore. Hamilton does not state, however, 
whether the estimate is for ore of shipping grade or for crude ore that 
must be concentrated, nor does he make any statement as to the depth 
to which mining must proceed to yield the tonnage estimated. 

At no other localities in Avery County, N. C., or Carter County, 
Tenn., are there known to be any deposits comparable in size to those in 
the strip of the Cranberry belt that have been mentioned, except perhaps 
at the Peg Leg mine, 3 miles south of Roan Mountain Station. Here 
there has been developed a body of good ore, the size of which, however, 
has not been determined even approximately. 

Elsewhere in these counties the veins are narrow and the ore-bodies 
too small to afford favorable conditions for cheap mining. In the 
aggregate a large quantity of ore might be obtained from them, but it 
would be in small lots at such widely scattered points that it could not 
be depended upon to furnish a continuous supply. There is no induce¬ 
ment to build a railroad to them, and without a railroad the cost of 
transportation over the hilly roads to the existing railroad would be 
prohibitive. 

In Ashe County, N. C., the three most promising explorations are 
near the Ballou place on North Fork of New River, near the mouth of 
Helton Creek (page 157), and on the Graybeal property (page 150) and 
on Piney Creek (page 146) near Lansing. On the North Fork are two 
adjacent explorations known as the “Home place” and the “Calloway 
property.” Both are in the same belt of deposits, the former north of 
the latter. At the “Home place” rather extensive explorations have 
been made, but no records of the results attained are now available. 
The “Calloway property” has also been explored, but not sufficiently 
thoroughly to prove the continuation of the vein, or to determine the 
presence of any wide portions. Consequently it is plainly impossible 
to estimate except in a very general way the quantity of ore in the area. 

On the supposition that a continuous vein 20 feet wide has been 
proven on the Calloway property, there are between the top of the hill 
and the river about 350,000 tons of magnetite above the river level. 
On the same assumption with respect to the “Home place” there are 
about 250,000 tons between the top of the hill and the river. In both 
cases the vein is supposed to yield 65 per cent, of merchantable ore. 

So far as we can now judge, that portion of the vein on the west 
side of the North Fork is at present of no value, since it is too narrow to 
bear the cost of mining and concentration. If, however, a concentrating 
plant were near at hand perhaps some portion of it might be mined 
with profit. 


SILICEOUS MAGNETITES 


81 


None of the ore on any of the three properties could he shipped 
without beneficiation. It would have to be concentrated before being 
placed on the market, since the amount of rich ore that might be picked 
by hand from the rock is too small to pay mining costs. A small con¬ 
centrating plant so situated as to take care of the product of these three 
properties and of any material that might be furnished by deposits 
father southwest on the same general belt might be made to pay, but 
no investment in any kind of mining or concentrating plant would be 
justifiable until some outlet to furnaces is provided. At present the 
nearest railroad is about 8 miles distant over hilly roads. 

The most promising of all the deposits in the county are those on 
the Graybeal property and at Piney Creek, near Lansing, principally 
because they are close to the railroad. On the Graybeal property there 
is indicated as available in the hill above the valley levels about 150,000 
tons, on the assumption that the vein is 17 feet wide and 800 feet long, 
and that it will yield 75 per cent, of merchantable ore. (See also page 
153.) At the Piney Creek locality about 65,000 tons are indicated above 
a depth of 100 feet below the level of the creek on the assumption that 
the vein is 12 feet wide and that its length is about 350 feet, or the dis¬ 
tance between the two most widely separated openings upon it. 

In either case some magnetic concentration would be necessary to 
secure the full yield, though at Piney Creek a large portion of the esti¬ 
mated yield might be produced by hand cobbing alone. The sizes of 
the deposits would not warrant the erection of an efficient concentrating 
plant, even though the output of both properties should be treated 
together. 


CHAPTER V. 


EXPLORATION 

PRELIMINARY STATEMENT 

One of the most striking characteristics of the mineral magnetite 
is its effect on a magnet, tending to draw the mineral and magnet to¬ 
gether. This property is not only made use of in concentrating magnetic 
ores, but is taken advantage of also in the search for ore bodies contain¬ 
ing magnetite. It is well known that the compass needle after swinging 
freely comes to rest in a position that is parallel to the line of magnetic 
force passing through the earth at the point on its surface immediately 
under the compass. This direction, in western North Carolina, is a 
degree or two west of north where there is no magnetite. The departure 
from the true north is known as the declination, and the direction to 
which it points as the magnetic north. Its amount is indicated on 
most of the topographic sheets issued by the II. S. Geological Survey for 
the year of publication. It increases a few minutes annually. In addi¬ 
tion to the pull of one end of the compass needle toward the north there 
is also a pull of the north end downward toward the earth. For this 
reason the south end of the needle in all compasses is weighted to make 
it swing horizontally. If not weighted the north end of a magnetized 
needle free to move vertically in the plane of the magnetic north will 
dip downward in latitudes north of the equator, provided there are no 
influences that interfere with the normal action of the earth’s magnetic 
currents. This vertical departure is known as the inclination, or dip, 
and the instrument made for measuring it the “dip needle.” 

The declination and inclination of a magnetized needle vary little 
from point to point over a rather broad area, unless some disturbing 
influence is nearby. If such a disturbing influence is in the neighbor¬ 
hood of the needle it will cause a variation in both declination and in¬ 
clination, depending upon the strength of its pull, and its distance and 
direction from the needle. A buried mass of magnetite will thus affect 
a compass and a dip needle, and from the strength and direction of its 
pull its position may be determined. The two instruments employed 
for rapidly locating magnetite are the “dial compass” and the “dip 
needle.” 

INSTRUMENTS EMPLOYED IN EXPLORATION 

THE DIAL COMPASS 

The dial compass (Figure 2), can be obtained from most dealers in 
engineering instruments. It is a small, portable sun-dial provided with 
a compass needle swinging inside a graduate circle, which, when the 
instrument is level, is horizontal. On a sunny day, if this instrument 


EXPLORATION 


83 


is set up, levelled, and turned until the shadow of the gnomon (a thread) 
falls on that division of the hour-circle which corresponds to the apparent 
time, the zero of the graduated circle will be in the true meridian, and 
the declination of the magnetic needle may be read off directly. In 



Figure 2. Dial Compass. 


order that the instrument may be set in the meridian and the correct 
declination read, it must be properly constructed, that is to say, the hour 
circle must be accurately graduated, the gnomon must make with the 
plane of the hour-circle an angle equal to the latitude of the place, and 
the zero of graduation must be in the vertical plane of the gnomon; 
the plane of the hour-circle must be level; and the apparent time must be 
known. To obtain apparent time requires two corrections to standard 
time; first, a correction for the difference of longitude between the place 
of observation and the standard meridian, and, secondly, the addition 
or subtraction of the equation of time, taken from the Nautical Almanac 
for the proper day and year. 60 . 

60 Much of the discussion of the use of the dial compass is taken from an article by 
H. L. Smyth: Magnetic observations in geological and econon ic work: Econ Geol vol 2 
p. 369, 1907. ” ' ' 






84 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Iii the correction for obtaining mean local time from standard time 
it is only necessary to multiply the difference in degrees between the 
longitude of the place of observation and that of the standard meridian 
(which is 75° for places using Eastern time and 90° for those using 
Central time) by 4. This will give the number of minutes that must 
be added to or subtracted from standard time to get mean local time. 
For convenience the watch may be set to give this time. In western 
North Carolina and the adjacent portion of Tennessee the product of 
the multiplication should be subtracted from the time of the 75° meridian 
and added to that of the 90° meridian. Thus the longitude of Asheville 
is about 82° 30' as read from the Asheville topographic sheet. This is 
7 }/ 2 ° (90°—82° 30'=7° 30') east of the 90° meridian. If reference is to 
Eastern time subtract 30 (7J^' X4) minutes to obtain mean local time, or 



Figure 3. Diagram illustrating the influence of a magnetic strip in producing hori¬ 
zontal deflections of a compass needle. (After H. L. Smyth.) 0-0 is line of no deflection. 

if reference is to Central time add 30 minutes. Thus at 10 o’clock Eastern 
time it is 9 o’clock Central time, and 9:30 o’clock mean local time at 
Asheville. To obtain apparent, or sun-dial time, the equation of time 
must be added to or subtracted from mean local time. The dial should 
then be set at the time indicated by the result. The zero point in the 
graduated circle will then face the true north. 

As has been said, in the presence of magnetic matter the compass 
needle no longer remains in the magnetic merdian but is deflected from 
it. The final position assumed depends on the direction and amount 
of the horizontal component of the force exerted and is the line of the 
resultant of this horizontal component and the horizontal component of 
the earth’s magnetism. The declination is then the angle which this 
resultant makes with the true meridian, and it is read in degrees. 





EXPLORATION 


85 


In the area of magnetic ores the ore deposits occur as long, narrow, 
probably deep lenses that are exposed on the surface as strips running 
parallel to the structure of the country rocks. The intensity of their 
magnetic force varies (a) with the quantity of magnetite they contain, 
(b) with its arrangement in the mass, and (c) with the directions of strike 
and dip of the deposits. It is greatest for rocks dipping in the direction 
of the earth s force and least for those which dip at right angles thereto. 

If the strip ot magnetic material is uniformly wide and dips vertically 
the horizontal component of its force acts at right angles to the strike 

/ 



Figure 4. Diagram illustrating the effect of the strike of magnetic strips upon the 
needle of a dial compass. (After W. O. Hotchkiss.-i 




80 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

of the strip (Figure 3). Its direction at all stations on the same side of 
the strip is the same and opposite to that on the other side; consequently 
the deflection of the needle will be different on the two sides, and between 
the two points at which the deflections are at their maximum values 
there will be a position over the strip at which there will be no deflection. 
A strip which strikes E-W. will produce no deflection except on its north 
side, and then only at such stations, near the strip, where the magnetic 
force of the magnetic material is greater than the pull of the magnetic 
north. A strip that strikes N-S. will produce equal deflections on both 
sides at stations equally distant, and a strip that strikes NE. or NW. 
will produce greater deflections on its northern side than at correspond¬ 
ing stations on its southern side. (Figure 4.) 

For instance, let P and P' be two stations on opposite sides of a 
vertical strip of magnetic ore striking NE. (Figure 3.) Let H repre¬ 
sent the strength of pull of the magnetic north, and H' the pull of the ore 
strip. Completing the parallelogram of forces by drawing lines from 
H and H' parallel to the direction of the forces, we have P'Hsand PHr 
as the resultants, or the directions assumed by the needle, and the 
angles HPHr and HP'Hr will be the declinations referred to the mag¬ 
netic north. Since the magnetic north is, however, about west of 

the true north, in the longitude of western North Carolina, the observed 
declination must be corrected by this amount to give the true declination. 
In actual work it is more convenient to refer declination to the magnetic 
north, and consequently this is always done, and the custom will be 
followed here. 

The points at which there are no declinations are always situated 
over the middle of the strip in the case of vertical layers, except where 
the strip strikes E-W., in which case it is indeterminate. The line join¬ 
ing these points of no declination indicates the strike of the strip. In 
the case of strips striking E-W. the strike is parallel to the line joining 
the points of maximum declinations, and the strip is south of this line. 

The points at which the local attraction LL is a maximum are de¬ 
termined by the fact that they are the points at which the declination 
of the needle is a maximum. They occur on each side of the strip and 
at equal distances from the magnetic line. This relation gives us a 
means of determining the cover over the strip if its width is known, 
or its width if the thickness of its cover is known, for: 

d? = K + a? (j) 

in which d is the distance of a point of maximum declination from the 
magnetic line of no declination measured at right angles to the strike 
of the strip; h is the depth of cover over the ore, and a is half the width, 
or thickness, of the strip. Since in most regions where magnetic ores 
occur the cover is not equally thick everywhere, and consequently the 


EXPLORATION 


87 


ore is nearer to the compass at some stations than at others, and, more¬ 
over, the strip is not equally wide everywhere, nor uniform in its con¬ 
tent of magnetite, the magnetic and maximum lines will rarely be straight. 
1 hey will curve more or less irregularly, but will on the whole follow a 
generally uniform course, so that there is rarely any difficulty in locating 
the general position of any ore belt within comparatively narrow limits, 
though its exact position at any given point may be somewhat doubtful, 
if only the record of the dial compass is considered. (See Figure 8.) 

All the relations discussed above relate to a strip of magnetic rock 
that dips vertically. Usually, however, the dip is not vertical but is 
more or less inclined to the vertical. Where the dip is high, as in the 
district under consideration, the correct location of the lines of maxi¬ 
mum and of no declination determines the dip of the ore body and also 
its boundaries. Smyth 61 has shown that when the dip is involved the 
equation given above (1) becomes 


h 2 + a 2 

a 2 = - 

Sin 2 dip 

In this case the line of no declination is not half way between the lines 
of maximum declinations, but is always nearer the maximum towards 
which the rock dips. This, therefore, gives us a means of determining 
the direction of dip. 

The location of the lines of maximum declination gives also some 
idea of the position of the boundaries of the magnetized strip, for its 
width can never exceed the distance between the two maximums. 

In the practical application of the method of declinations to pros¬ 
pect an ore body, it is simply necessary to set one’s watch to dial time, 
as explained above, and then occupy successive stations on lines crossing 
the deposit perpendicularly and read the declinations of the needle, after 
setting the compass so that the shadow of the thread will fall on the 
corrected time indicated by the watch. It is best to place the compass 
on a jacob's staff or a tripod to hold it steady, and to read after the needle 
settles. Usually it is satisfactory to cross the strip at intervals of about 
20 feet and make observations at intervals of 10 or 12 feet. There is 
no need to locate the stations beforehand. It is only necessary to stop 
every 10 feet as the strip is crossed and to set the compass at these stops. 
After all observations are correctly plotted it is easy enough to draw 
lines through the points of maximum and zero declinations and from 
the plot, to determine to position, dip and extent of the magnetic strip. 
If it is discovered during the course of the plotting that a mistake has 
been made in assuming the direction of strike, it is easy enough to 


61 Smyth, H. L., Trans. Amer. Inst. Min. Eng. vol. 26, p. 645, 1896. 




88 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

change the traverses across the strip so that they will be at right angles 
to its strike. 

THE DIP NEEDLE 

The dial compass registers the strength of the horizontal compo¬ 
nent of the magnetic force by which it is influenced. The dip needle 
registers its vertical component. The dip needle is a more rapidly act¬ 
ing instrument than the dial compass and 
for preliminary work is quite as satisfactory. 
It consists of a magnetized needle so pivoted 
as to swing in a vertical plane when sus¬ 
pended loosely from a support, usually the 
hand. (Figure 5.) To avoid the effect of 
the horizontal component of the magnetism 
the instrument must be held in the magnetic 
meridian, i. e., it must be held so that its 
vertical plane makes the same angle with 
the true north as does the compass needle. 
The amount of deflection from the hori¬ 
zontal is read on a vertical graduated circle 
and plotted at the point representing the 
position of the station occupied 62 , indicat¬ 
ing with a plus sign depressions of the north 
end of the needle and with a minus sign 
depressions of its south end. Lines are 
drawn between the points of equal deflec¬ 
tions (see Figure 6), and inferences as to 
the extent of the magnetic body are de¬ 
duced from the map thus produced. 63 

In practical work the dip needle is first tested at some place where 
there is known to be no local attraction and its deflection is noted. This 
serves as the zero point against which other deflections are read. If the 
needle is accurately balanced for the district being studied the divergence 
from the zero gradation in the vertical circle will be nothing and the 
deflections due to local attractions are read directly. In the mountains 
the stations occupied may be the same as those occupied when reading 
the dial compass, but if only the dip needle is employed it should be 
read at intervals of about 40 feet crossing the belt and perhaps 60 feet 
along its strike. It is impossible to discuss in detail the method of inter¬ 
preting dip maps. Messrs. Broderick and Hotchkiss have done this in 
an admirable manner in the two articles referred to above. In brief, 



62 For discussion of construction of dip needle and theory of its action see: Hotchkiss, 
W. O., Mineral land classification: Wis. Geol. and Nat. Hist. Survey, Bull. 44, pp. 75-125 
1915. 

63 See Broderick, T. M., Some features of magnetic surveys of the magnetite deposits 
of the Duluth gabbro: Econ. Geol., vol. 13, p. 35,1918. 



EXPLORATION 


89 



















90 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


however, it may be stated that the attraction at any point may be con¬ 
sidered as being made up of two components: (1) the normal attraction 
of the earth as determined at some point far from railroad tracks, trolley 



Figure 7. Diagram illustrating the effect of a buried magnetic strip upon a dip 
needle at different positions and the method of determining the depth to the magnet. (After 
W. O. Hotchkiss.) 

wires or other disturbing influences, and (2) the local attraction due to 
buried magnetized bodies. In Figure 7 the effects of these two factors 
are shown at 3 points in a traverse across a steeply dipping magnetic 



Figure 8. Diagram illustrating the use of the dial compass and dip needle to trace 
a magnetic line in Florence County, Wisconsin. The large figures are angular deflections 
of the compass needle, and the small figures are declinations of the dip needle. 

The diagram shows the importance of combining dial and dip readings to detect the 
course of a magnetic strip. Had dial readings alone been considered the strip might have 
been thought to continue to the northwest. (After W. O. Hotchkiss.) 






















EXPLORATION 


91 


layer. The lines Hr represent the magnitudes and directions of the at¬ 
tractions observed at points where Hn represents the direction and 
magnitude of the earth's normal attraction and Hl the corresponding 
factors of the local attraction. Hr is the resultant of Hn and Hl. If 
the strength and direction of the earth's attraction 64 is known, since 
H* is the observed dip of the needle, Hl can be plotted by completing 
the quadrangle of which Hr is the diagonal. This line will then give 
the direction of the local attraction from the point of observation. If 
three or four observations are made and the lines Hl are projected down¬ 
ward their points of intersection will indicate the approximate position 
of the attracting body. The matter of depth is not important in the 
case of the deposits in the mountain district because the ore bodies either 
outcrop or are so near the surface that they behave toward the dip 
needle as though outcropping. The principal use of the needle is to 
detect the deposit and serve as a means of estimating its approximate 
length and breadth. It is employed principally for confirming the in¬ 
dications of the dial compass. Moreover, since its use does not depend 
upon the sun it may be employed on cloudy days for detecting the ap¬ 
proximate position of a magnetite deposit preliminary to more accurate 
work with the help of the dial compass. Figure 8 illustrates the method 
of tracing a curved magnetic line by combining the records of dial com¬ 
pass and dip needle. 



THE MAGNETOMETER 

From the observations made with the dial compass or the dip needle 
the presence of a layer of magnetite of reasonable size, its dip and ap- 

S4 For the method of determining the intensity and direction of the earth’s magnetism 
and the intensity indicated by the vibrations of the dip needle, reference should be made 
to the article of‘W. O. Hotchkiss, op. cit. pp. 125-136. 














MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


92 


proximate width may be determined. But the determination of these 
features does not afford an accurate means for deciding as to its size. 
This may be better accomplished by the use of the Thalen-Tiberg mag¬ 
netometer (Figure 9), which is an instrument designed for making ob¬ 
servations in the vertical as well as the horizontal plane, and for record¬ 
ing their intensities directly. It is a much more difficult instrument 
to use than either the dip needle or the dial compass, and its use requires 
that the area to be examined shall first be surveyed and stations estab¬ 
lished. Moreover it is slower working than either of the other instru¬ 
ments and consequently a survey made by it is much more expensive. 65 
If it is desired to employ it to outline a little more accurately than can 
be done by the use of the dial compass or the dip needle, its manipula¬ 
tion should be entrusted to a professional engineer who is familiar with 
magnetic surveys. A skilled engineer may determine the size of the 
area underlain by magnetic material and may outline its borders, but 
even with the aid of the most precise instruments he cannot determine 



Feet 


loo -»© ° too /OO -SOO 400 Wo 

Figure 10. Map showing isodynamic lines over a belt of magnetic rock of practically 
uniform width outcropping freely in a rough country. The irregular courses of the lines 
are due mainly to the fact that the distance of the magnet from the instrument varied widely 
because of the irregular surface. (After H. L. Smyth.) 

In outlining the size of a magnetite deposit the readings of the 
magnetometer are plotted as in the case of the dip needle and dial com¬ 
pass and a map is made by joining the points of equal and similar inten¬ 
sities by lines. Positive intensities are indicated by one color and nega¬ 
tive intensities by another. Maps of this type are known as isoclinal 
or isodynamic charts, as they delineate the vertical or horizontal inten¬ 
sities. Their general features are shown by Figure 10 and by Plate 
XIX, which is a reproduction of a map made by Mr. S. H. Hamilton 
in the vicinity of the Wilder mine. 


SAMPLING 


The value of a deposit depends upon its size and its composition. 
Deposits of magnetic ores owe their value as economic sources of iron 
ore to the abundance of magnetite in them. Most of them have to be 


t5 For a discussion of the magnetometer see Smvth, H. L., 
horizontal instrument: Econ. Geol., vol. 3, p. 200, 1908. 


The magnetometer as a 


































































































EXPLORATION 


93 


concentrated before use in the furnace and the cheapest methods of con¬ 
centration are based on the magnetic property of their ore-mineral. 
Some of the minerals associated with the magnetite are iron-bearing, 
but since they are not sufficiently magnetic to be attracted by the magnets 
employed in concentrating plants they pass into the tailings and their 
iron content is lost. It is necessary, therefore, to determine the propor¬ 
tion of magnetite to gangue in a deposit before it can be decided whether 
it will yield sufficient magnetite to pay for mining and concentration. 
Phis may be done by making a magnetic separation of the magnetite 
from the gangue in crushed samples representing the average of the ore 
body. As chemical analysis is more convenient and cheaper than mag¬ 
netic analysis, when small samples are involved, it is better first to 
determine the quantity of available iron present in an average sample 
to discover whether it is advisable to make a magnetic separation or 
not. If results are favorable it may be well later to subject large samples 
to magnetic analysis by running quarter ton lots through a concentrator 
after they have been crushed to the proper size. (Compare page 0>9.) 

The satisfactory sampling of ore-bodies like those in the pre-Cam¬ 
brian rocks of western North Carolina and East Tennessee is a diffi¬ 
cult accomplishment because of the coarseness of the material and its 
rude banding. In order that samples may correctly represent the ore- 
body they must contain gangue and ore in the same proportions as these 
exist in the deposit. The tendency of the prospector is to discard sam¬ 
ples containing little or no magnetite and to select those that appear to 
lie rich in ore. If this is done the samples serve no important purpose 
because they will not represent the ratio of gangue to ore in the ore- 
bodv. It is well to cut trenches to the solid ledge across the full width 
of the deposit at intervals of 100 feet. To avoid unintentional selection 
a cord should be knotted at equal intervals of 3 or 4 feet and stretched 
the length of the trench, and, as nearly as possible, equally large samples 
of generous size should be broken from the ledge at the places indicated 
by the knots. These should be numbered and the corresponding num¬ 
bers inserted on a map. The samples should then be analyzed for iron, 
phosphorus and sulphur, and the results also indicated on the map under 
the proper sample number. In this way the distribution of the pay ore 
at the surface might be learned and this might lead to a decision whether 
or not it would be worth while to sample more thoroughly. If the sur¬ 
face samples are promising further examination should be undertaken 
with the diamond drill, under the direction of a competent driller. The 
drills should be of such a size as to produce a core an inch in diameter 
and should be so placed as to cut across the deposit. 

A great deal of care is necessary to secure a satisfactory core that will 
represent accurately the material drilled, and consequently it is much 
more desirable to have the whole operation of drilling directed by an 


94 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 



Figure 11. Map of isodynamic lines over a series of magnetic lenses near Ringwood, New Jersey, illustrating the use of a magnetic map for plan¬ 
ning a drilling campaign. (After S. H. Hamilton.) 

Three ore lenses dip nearly vertical, and pitch at a moderate angle to the northeast. The westernmost lens should be explored by diamond drill¬ 
ing between the stations E and D, the middle lens between B and C, and the easternmost at about A. 




























































EXPLORATION 


95 


engineer than to attempt it without such supervision. In all cases the 
cores should be carefully and distinctly labelled with the number of the 
drill hole and the depth at which obtained. The positions of the holes 
should be carefully selected (compare Figure 11) and should be plotted 
on the surface map on cross-sections through the deposit and the char¬ 
acter of the rocks cut through should be indicated in the proper places. 
Samples of the ore layers should be taken from the cores at fairly close 
intervals and analyzed for iron, phosphorus and sulphur, and the results 
of the analyses plotted on the cross-sections. Upon combining the 
cross-sections and the surface map and drawing lines through the various 
points outlining the areas within which analyses show the presence of 
ore of value, the size of the ore-body can be determined and its tonnage 
estimated. As the gangue of the magnetite ore is mainly hornblende 
it is easy to calculate the approximate tonnage of magnetite present in 
a deposit if the ratio of magnetite to gangue is known. About 7 cubic 
feet of pure magnetite weigh one ton, and 10 cubic feet of hornblende. 
If the crude ore consists of a mixture of 30 per cent, magnetite and 70 
per cent, of gangue, it will recpiire 9.1 cubic feet to constitute a ton, 
and of this weight 30 per cent, will be pure magnetite. 

Before plotting drill holes their actual positions and courses should 
be determined accurately. Very rarely does a drill hole follow a straight 
course through rocks like those associated with magnetite ores. Mr. 
Hamilton 6r> declares that all drill holes in such rocks will begin to meander 



««Unpublished report of the Tennessee Geological Survey. 








90 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

appreciably after reaching a depth of several hundred feet, and the 
greater the depth the greater will be their departure from a straight 
course. The meandering is least where the drilling is perpendicular to 
the dip of the formation. In some cases the deviation of a drill from 
a straight line is so great that it may not touch the ore-body to which 
it was directed and thus may give an entirely erroneous impression of 
the underground conditions. Figure 12 sketched by Mr. Hamilton, 
illustrates this point. 

In view of the known deviation of drill holes from the direction in 
which they are started, it becomes necessary to survey them before 
plotting, in order that the actual position of any ore-bodies cut by them 
may be determined. Experience has shown that they must be tested 
at intervals of about 150 feet for both course and inclination. This is 
done by lowering into the hole a small tube into which some fluid etching 
agent is enclosed, and freeing the fluid at the depth at which the test is 
to be made, thus allowing it to etch the wall of the tube. By carefully 
controlling the lowering of the tube and noting its revolution during its 
descent, data are obtained from which the position and inclination of 
the tube can be calculated; and from the relative positions of the tube 
at successive intervals of depth the course of the hole can be determined 
and plotted. Since, however, this procedure is a complicated one, it is 
not practicable for any one not an experienced engineer to employ it 
successfully. 

Thus, while the preliminary examination of an ore deposit might 
well be undertaken by any intelligent man, its thorough examination 
should be entrusted to an engineer in good standing, before any large 
amount of money is spent in developing it. 


CHAPTER VI. 


MINES AND PROSPECTS IN SILICEOUS 

MAGNETITES 

GENERAL FEATURES 

Only one mine, that at Cranberry, is now working in the siliceous 
magnetites. Formerly several others were operated for short periods 
on deposits like those at Cranberry, but after the best ore near the sur¬ 
face had been taken out the mines were abandoned, in most cases before 
they had been thoroughly explored. At a few places explorations have 
been fairly extensive. Some places have been abandoned because no 
large deposits were developed; others, because the crude ore required 
concentration before suitable for the furnace, and still others because 
too far from railroads. In most cases the records of the explorations 
have been lost, and there is now available no information as to what the 
work disclosed. Most of the openings in the district are small pits that 
furnished ore to the old forges that were scattered through the mountains, 
but very few of these went down into the solid rock. In some places 
the ore fragments were picked from the soil by hand; in others the soil 
was washed and boulders and finer fragments were shipped together. 
Other openings are pits and trenches that uncovered solid rock. These 
were used in prospecting, and when the width of the ore body had been 
exposed work ceased. Many of these openings have now been filled by 
wash, but some still show the rock. 

Nearly all the information available as to the relations of the ore 
to the veins in which they occur has been obtained either from the open¬ 
ings of the Cranberry mine or from the material in the dumps of the aban¬ 
doned mines. The prospect pits have been of value in showing that 
the veins on which they are situated are like the vein at Cranberry. 
The old pits serve to locate the positions of veins not now exposed. 
Descriptions of most of the older veins are to be found in the report by 
Mr. Nitze 67 on the iron ores of North Carolina. Some of these are re¬ 
produced in the following pages, and many references have been made 
to them. References are also made repeatedly to an unpublished report 
bv Mr. S. II. Hamilton to the Tennessee Geological Survey for descrip- 
tions of deposits not seen by the writer. 

CARTER COUNTY, TENN., AND AVERY AND MITCHELL 

COUNTIES, N. C. 

THE CRANBERRY BELT 

The only mine in the State producing siliceous magnetite is at 
Cranberry in Avery county, N. C., on the East Tennessee and Western 

67 Xitze, H. B. C., Iron ores of North Carolina: North Carolina Geol. Survey. Bull. 1, 
Raleigh, 1893. 




98 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


North Carolina R. R., about 32 miles from Johnson City, Tenn. Al¬ 
though other deposits have contributed to the output of magnetic ore 
from time to time the Cranberry mine has been operated almost con¬ 
tinuously for many years and has contributed a tonnage many times 
greater than that of all the other mines combined. Its ore is famous 
because of its low content of phosphorus, and the metal made from it 
has been eagerly sought by manufacturers desiring unusually tough iron. 
The character of its ore, however, presents no specially peculiar features. 
There are many other deposits that might furnish ore of the same qua¬ 
lity if the quantity were known to be great enough to warrant the erec¬ 
tion of a plant of sufficient capacity to keep the mining costs at a rea¬ 
sonable figure. 

Careful mapping of the known deposits in the two counties suggests 
that most of the non-titaniferous magnetite ores lie in a belt that follows 
the structure of the country from Cranberry west and southwest to the 
Toe River (Plate I.), beyond which no openings have been made and 
no outcrops of ore have been reported. The Big Ivy mine in Madison 
County is about 25 miles southwest of the point at which the line of open¬ 
ings in Mitchell County crosses the Toe River and this is thought by 
Nitze to be in the same belt. Since the deposits immediately north of 
the Toe River are widely scattered and no connection has been traced 
between any one of them and the Big Ivy mine, it is more reasonable 
to regard the Cranberry belt as ending at the river, than to suppose that 
it extends to the Big Ivy mine. 

This belt of deposits is the most conspicuous in the State. Its best 
known deposit is at Cranberry where the Cranberry mine has been oper¬ 
ating since 1876, and from which, before this time, ore had been taken 
for the use of Catalan forges as far back as 1820. The belt extends at 
least as far east as Vale, which is 4 miles southeast of Cranberry, beyond 
which Cambrian sediments cover the pre-Cambrian rocks in which the 
magnetites occur and consequently prevent farther tracing of the belt. 
To the west it extends across into Tennessee to beyond Doe River, a 
distance of 8 miles. Here it is lost as a distinct belt but a few deposits, 
between the Horse Shoe mine on Doe River and Magnetic City may 
mark its course. Nitze 08 thinks that it bends to the southwest, passes 
close to Magnetic City and continues south and southwest toward Re¬ 
lief on Toe River. Near Toe River are a number of small deposits, but 
they are distributed over a strip of country 2J/^ miles wide, and are 
therefore not in a definite belt, like that at Cranberry. 

CRANBERRY MINE 
General description of mine and ore 

The most notable deposit in the belt running from Vale to the Doe 
River is, as has been said, at the Cranberry mine, on the east slope of 


68Qp. Cit., pp. 168-182. 



PLATE XII. 



View of Cranberry mine, Cranberry, Avery County, North Carolina. Looking northwest along the vein. 




















100 


MAGNETIC IRON ORES OF EAST TENN . AND WESTERN N. C. 


Cranberry Ridge. (See Plates XII and XIII) In 1876 the mine 
came into the possession of its present owners and in 1882 it was con¬ 
nected with Johnson City by rail. In 1884 a small blast furnace was 
built and smelting of the ore was begun. Later, in 1900, this furnace 
was abandoned, a larger one having been built by the Cranberry Fur¬ 
nace Co. at Johnson City (Plate XIV), and since May, 1902, the ore has 
been smelted there. The capacity of the furnace is 100 tons of pig 
iron daily, and the Cranberry mine furnishes most of the ore from which 
the iron is produced. Since 1884 the mine has produced about 1,250,000 
tons of merchantable ore, during the past 4 years (1917-18-19-20) at 
the rate of about 60,000 tons annually. The mine was closed tem¬ 
porarily in January, 1921, but was again working in 1923. 

The ore as it comes from the mine is a non-titaniferous magnetite, 
which may be almost pure, or which may be intimately mixed with 
hornblende or with hornblende and other components of the gangue 
to be described later. Formerly the pure ore was separated from the 
leaner product by hand-picking, and the leaner ore was crushed to a 2-inch 
size, fed into a log-washer and from this to a screen for sizing, and after 
sizing the various portions were carried past magnets by which the 
richer material was separated from the lean portions, which were carried 
to the waste piles. The finest portions passing the screen were washed 
by a stream of water to a separate magnet by which the ore was con¬ 
centrated. The concentrates were then screened by a 10 mesh screen 
into finer and coarser portions. During the last two years all the ore 
was shipped to the furnace as mined, without further concentration 
than hand-picking. 

The chemical character of the ore and the effect upon it of mag¬ 
netic concentration has already been discussed on pages 52 and 69. 
All the analyses given on these pages were for commercial purposes and 
are only partial. Two complete analyses were made by the chemists 
of the Tenth Census' 59 , one of a selected sample of nearly pure magnetite 
( B ) and the other of a mixture of magnetite and epidote representing a 
lean ore (^4). These are quoted below. A third analysis of a selected 
sample was made by Mr. J. G. Fairchild of the United States Geological 
Survey. This is recorded below under (C) The figures under ( D ) 
represent the composition 70 of the shipping ore from the south vein of 
the Richard mine, Morris county, N. J. 

69 Willis, Bailey, Notes on samples cf iron ore collected in North Carolina: 10th Census 
U. S., vol. 15, p. 326, 1886. 

70 Bayley, W. C., Iron mines and mining in New Jersey: Geol. Survey of New Jersey: 
vol. 7 cf the Final Report Series of the State Geologist, p. 113, 1910. 




PLATE XIII. 



View toward‘Smoky Mountain’ looking east from Cranberry, Avery County, North Carolina. The Cranberry 
vein runs across the mountain to the left of the high peak. 





102 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 




A 


i 

D 

r 

D 

Silica. 


29.99 

29.99 

5.27 

5.27 

14.28 

8.48 

Alumina. 

. (AL0 3 ) 

10.07 

4.63 

1.18 

1.41 

1.08 

.86 

Ferric oxide. 

. (Fe 2 0 3 ) 

25.05 


62.57 


50.35 

55.99 

Ferrous oxide. 

. (FeO) 

18.93 

3.78 

26.68 


28.30 

26.98 

Magnesia. 

• (MgO) 

1.78 

. 56 

. 55 

.26 

.62 

1.89 

Lime. 

. (CaO) 

11.33 

4.62 

1.46 

. 52 

5.18 

2.42 

Soda. 

. (Na 2 0) 


.07 



.37 

.33 

Potash. 

.(ICO) 


. 10 



Tr. 

. 19 

Water at 110°. 

. (H 2 o-) 

.37 


.35 


. 04 

| . 15 

Water above 110°'... . 

.(HoO+) 

1.49 


.49 


. 17 


Titanium dioxide. . . . 

. (TiOo) 



. 95 


. 12 

1.01 

Carbon dioxide. 

• (CO,) 

.07 


.08 


None 


Phosphorus pentoxide 

(P 2 0 5 ) 

.024 


.007 


None 

1.54 

Pvrite. 

. (FeS 2 ) 

. 18 


.20 




Nickel sulphide. 

. (NiS) 

.09 


.04 




Sulphur. 

.(S) 





None 

.008 

Sulphur trioxide. 

• (SO,) 





Tr. 


Vanadium pentoxide . 

. (V 2 0 3 ) 





None 

.08 

Manganous oxide.... 

. (MnO) 

. 76 


. 22 


. 18 

.02 

Chromic oxide. 

. (Cr 2 0 3 ) 





None 

None 

Baryta. 

.(BaO) 





None 

None 

Strontia. 

. (SrO) 





None 

None 

Fluorine. 

• (F) 





None 

.08 

Total. 


100.134 


100.047 


100.69 

99.948 

Insoluble. 


43.60 

43.75 

7.20 

7.46 



Iron. 

• (Fe) 

33.37 


64.64 


57.25 

60.19 

Sulphur. 

• (S) 

>128 


. 115 



.008 

Phosphorus. 

• (P) 

.010 


.004 



.672 

Phosphorus ratio .... 

. (P:Fe) 

.031 


.006 



1.115 


The ore is notable for its low content of phosphorus and sulphur. 
It differs from the titaniferous magnetites in its low content of Ti0 2 
and in the absence of Cr 3 0 3 (see page 19.) It is very similar to the 
ore in the gneisses of New Jersey, but contains less phosphorus and less 
titanium. Moreover, vanadium is present in the New Jersey ore and 
in all other New Jersey magnetites in which it has been sought, whereas 
it is absent from the Cranberry ore and, so far as known, from all other 
North Carolina magnetic ores. 

The Cranberry vein, which encloses the deposit at the mine, has been 
traced for 6,400 feet by pits, cuts and underground working, so that it 
is regarded as being continuous through this distance. (Plate XV.) 
It is not so, however, with the workable ore. There are stretches of 
the vein that contain such small quantities of available magnetite that 
they may be regarded as barren. At other places the magnetite is in 
sufficient quantity to warrant mining. In all cases the ore-bodies lie 
within the vein, but they are separated from one another by lengths of 
the vein that are occupied mainly by gangue. (Plate XVI.) But even 
in these portions there is always a little magnetite in strings or threads 



























PLATE XIV. 



Cranberry Furnace, Johnson City, Tenn 




























104 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

connecting the larger masses (the ore-bodies) with one another. In 
response to an encpiiry made to President Howe of the Cranberry Fur¬ 
nace Co. the statement was made that in going north in the Cranberry 
mine, while at times the workings “passed through barren places where 
the ore almost entirely disappeared, it has in every case been the fact 
that it did not entirely disappear, and there was always a little thread 
of ore connecting together" the different deposits. Moreover, it is 
true that in each of the openings on Smoky Mountain, southeast of the 
mine proper, “both at the south and north ends, as far as we have gone, 
there has been at least a little thread of ore left indicating the possibility 
of their leading on to another lens.” 71 

The country rock surrounding the vein consists of a crushed and 
sheared complex of acid feldspathic rocks, some of which are dark gray 
and others almost white, occurring in alternating layers with black 
gabbroitic gneiss, believed by Keith 72 to be portions of the Roan gneiss 
which have been intruded into the more acid rocks. The lighter coiored 
layers constitute by far the greater part of the complex, which has been 
called by Keith the Cranberry granite. 73 

The vein follows the schistosity of the country rock. It varies in 
width from a few feet to 200 feet and is extremely complex. It com¬ 
prises a plexus of rocks in the midst of which occurs the commercial ore 
as a series of lenses, which so far as development has gone, appear to 
have no pitch. The plexus is cut by pegmatite and by veins of almost 
pure magnetite. The pegmatite cuts irregularly through the vein plexus 
twisting and turning in a complicated way and gradually fingering out. 
In some places it encloses lenses of ore and in others lenses of coarse, 
green hornblende. In places it cuts comparatively cleanly through 
the other rocks, often with only one sharp wall, rarely with both walls 
sharp. Usually the walls are indefinite—the pegmatitic material grad¬ 
ing into gneiss, so that frequently there is a little seam of gneiss between 
the pegmatite and the vein matter. 

The main portion of the vein, aside from the horses that occur in 
it and the veins of pegmatite and magnetite, consists of masses of horn¬ 
blende, or of hornblende and magnetite, of hornblende and epidote, of 
epidote and magnetite, or of epidote and quartz, with occasional small 
quantities of molydenite. 74 

Descriptions of the ore and of all the gangue rocks associated with 
it have already been given in a general way and their relations have 
been discussed on pages 48 to 67. It will not be necessary to repeat 
these statements but, since at some of the openings there are exhibited 

71 Letter of Mr. F. P. Howe, President, dated Johnson City, August 27, 1919, and reply 
thereto by Mr. S. H. Odom, Superintendent of mine, dated Cranberry, August 28, 1919. 

72 Keith, Arthur, U. S. Geol. Survey Geol. Atlas, Cranberry folio (No. 90), p. 8, 1903. 

7S The Cranberry granite and Roan gneiss have been described on pages 39 to 46. 

7 «Hamilton, S. H., Unpublished report to Tennessee Geol. Survey 



PLATE XV. 



Map of surface. Cranberry mine, Cranberry, N. C., with projection of underground workings. (Based on map by S. H. Hamilton, furnished 
by the Cranberry Furnace Co.) 











































106 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

special features that throw considerable light on the method of origin 
of the vein, brief descriptions of these will be given at the risk of repeating 
some of the statements that have already been made. 

Smoky No. 1 

The southeasternmost opening in the Cranberry mine tract is at 
the head of a ravine on the north slope of Smoky Mountain about 
three-quarters of a mile southeast of the main opening of the mine. 
The exposed portion of the vein widens and narrows by rolls in the hang¬ 
ing-wall, in some places being only 4 inches wide. Its general dip is 
southeast and both hanging and footwall are Cranberry granite. (See 
Plate XVII, A, and page 45.) The vein contains a great deal of 
epidote. In some places it consists exclusively of epidote and dark- 
green hornblende cut by quartz veins. Nearly everywhere it is bordered 
by a narrow seam of epidote rock which swells out at places into a coarse¬ 
grained aggregate of epidote, quartz, and idiomorphic hornblende. 
This coarse rock is plainly a pegmatite in which the feldspar has been 
changed to epidote. On the dump are fragments which show small 
masses of partially epidotized feldspar in the midst of nearly pure epidote- 
quartz aggregates. The hornblende is a greenish-black variety varying 
greatly in abundance in different portions of the pegmatite. It is entirely 
absent from some specimens, but it occurs in others forming crystal 
groups an inch in diameter, or, where in large quantity, forming lenticu¬ 
lar masses that may be several inches or even several feet in length. 
Magnetite is always present where hornblende is abundant. It may 
occur in little streaks on the borders of the hornblende groups, or it may 
be scattered through them. Often the larger lenses are in reality granu¬ 
lar mixtures of hornblende and magnetite, or granular aggregates of 
hornblende with little lenses of magnetite scattered through them. In 
some cases also short thin seams of magnetite and small lenses of the 
same mineral are to be found in the midst of the epidote, but this is not 
common. The magnetite and hornblende are so intimately associated 
that it is difficult to escape the suspicion that they are genetically con¬ 
nected. 

Another feature that is prominent in all the pegmatite in this open¬ 
ing is the apparent schistosity of the rock. The lenses of hornblende, 
of magnetite and of the mixtures of the two and large isolated crystals 
of hornblende are all elongate in the plane of the vein. The quartz, 
however, rarely shows this parallelism to a marked degree and the 
epidote never. 

The ore is mainly toward the center of the vein between the streaks 
of epidote rock near its borders. It is the usual mixture of hornblende 
and magnetite cut here and here by strings of nearly pure magnetite. 
(Seepages 52 to 58.) In the midst of the vein is a banded gneiss that looks 


PLATE XVI. 


t 















108 


MAGNETIC IRON ORES OF EAST TENI- 


AND WESTERN N. C. 


like a schistose diorite, and it is noticeable that the feldspar in it is pink 
and shows little trace of epidotization. The miners state that the rock 
is a horse in the vein, which plays out along its strike and often continues 
in the ore as partings. Moreover in this opening a small diabase dike cuts 
the ore lengthwise, but this is not significant, as similar dikes occur in 
the granite at some distance from the vein. 

The material of the “horse” is a distinctly gneissic, somewhat 
fissile, gray and white mottled rock, with occasional white feldspar 
streaks and chlorite partings parallel to the schistositv. The mottlings 
are due to the presence of fragments of decomposed plagioclase (mainly 
oligoclase), scattered through a dark-gray matrix. The centers of the 
grains contain numerous small prisms of a light-colored epidote (prob¬ 
ably zoisite), but they are surrounded by broad rims of newer plagio¬ 
clase entirely free from decomposition products. The feldspar fragments 
are embedded in an rggregate of quartz, feldspar, plates and spicules of 
hornblende, and nests of yellow-green epidote. The quartz and epidote 
form a mosaic and the hornblende occurs as clumps in this mosaic as 
though representing grains of some mineral that has otherwise completely 
disappeared. Although the greater part of the hornblende is in the 
mosaic many spicules extend into the rims around the larger grains of 
feldspar and some penetrate into their altered nuclei. Many of the 
feldspar grains are granulated on their edges and nearly all show curved 
twinning lamellae. 

Horses of this kind are not notably different from the more common 
varieties of Cranberry granite. They are apparently portions of the 
granite that have been enclosed in the vein and greatly metamorphosed. 
Their principal difference from the granite is in the greater proportion 
of hornblende and epidote in them. 

Mention has been made of the fact that as a rule there is a narrow 
layer of epidote on the outside of the vein. This is usually between the 
ore and the walls; but at one place a little lens of ore, composed of the 
usual granular mixture of hornblende and magnetite, separates the epi¬ 
dote from the hanging wall. Between the ore and the wall is a gouge 
of chlorite mixed with particles of magnetite. 


Smoky No. 2 

The next important opening on the mountain is the pit and tun¬ 
nel known as Smoky No. 2. It is about 1,100 feet northwest of the 
opening just described and 250 feet below it. At the end of the tunnel 
the vein can be seen to be 8 feet wide and to dip about 20° SW. The 
dip rises to 32° in some places, said to be due to rolls mainly, if not ex¬ 
clusively, in the hanging-wall. Between the Cranberry granite and the 
vein-mass on both walls are gouges of shaly or slaty ehorite schist. This 
gouge is about l l /2 inches thick on the hanging-wall and consists almost 


PLATE XVII 



(A) 



( B) 


(A) Smoky Xo. 1 opening, Cranberry mine, showing platy structure of hanging- 
wall granite. 

( B) Part of wall, open cut, Cranberry mine, showing irregular distribution of 
ore. All the rock in view is vein-filling. 





110 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

solely of chlorite. The ore-matter is composed of a mixture of magnetite, 
hornblende, epidote and quartz, cut by veinlets of magnetite, and here 
and there by veinlets of epidote. The richer portions contain a greater 
number of magnetite veinlets or a few larger veins. Some of the latter 
are themselves cut by small calcite veins and by tiny streaks of pyrite. 
Ore of this kind is massive, or very slightly schistose. It is composed 
of large crystalloids of magnetite and in addition garnet in some places. 
A microscopic description of the ore is on page 56. A parting in the 
ore consists of very fine-grained epidote with parallel streaks of quartz. 
Its surfaces are covered with a thin coating of the same chloritic gouge 
that occurs on the walls of the vein, indicating movement in the ore-body 
after it became solid. 

On the dump at the tunnel are many large fragments of ore and 
vein-rocks that afford a better view of the relations of these to one 
another than can be seen on the walls of the tunnel, and also great frag¬ 
ments of a very feldspathic weakly schistose gneiss that is said to occur 
as a “horse.” The feldspar of this gneiss is pink and fresh, and the 
rock shows no trace of epidotization. Under the microscope the rock 
is seen to be composed of large orthoclase and oligoclase or andesine 
grains, broken across, crushed on their edges, and often separated into 
sharp-edged fragments, surrounded by a quartz-feldspar mosaic contain¬ 
ing numerous small plates of a yellowish-green biotite, that lie between 
the larger grains and wind around them. Other sections contain a 
great deal of granular epidote and a few wisps of green hornblende. 
The rock apparently is a crushed Cranberry granite. 

The greater portion of the vein-filling is a foliated gneiss composed 
of alternating feldspathic and hornblendic layers. The feldspathic 
layers appear to have intruded a series of alternating layers of hornblende 
schist, sugary quartz and finely granular epidote making up a portion 
of the vein mass at this place. Certain of the feldspathic streaks appear 
to extend into the schists and to terminate in quarz-epidote veins; in 
other places they swell into pegmatite lenses. 

Within this vein-mass are lenses of quartz and veins of granular 
epidote ranging from a tiny fraction of an inch to an inch or more in 
thickness. In many places, especially where they are in contact with 
hornblende, the epidote veins are bordered by narrow zones of magnetite. 
Lenses and veinlets of pure magnetite also occur in the hornblende 
layers. In some places the magnetite lenses seem to be isolated but in 
most places they are connected by small veins of magnetite. Those por¬ 
tions of the hornblende layers that are most closely crowded with the 
lenses and veins constitute the commercial ore. In some specimens the 
hornblende is extremely fine-grained and schistose, and where it breaks 
away from lenses of magnetite embedded in it the contact surfaces are seen 
to be coated with chlorite. Moreover, much of the hornblende in the schist 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


111 


layers is also apparently chloritized. Evidently there has been move¬ 
ment within the vein since its solidification. This is also evidenced by 
the fact that the pegmatite lenses which are common in the foliated 
gneiss are in some places crushed into their component feldspar and quartz 
grains, so that their grains, especially the feldspar grains, are separated 
from the main mass of the pegmatite and surrounded by films of the 
hornblendic schist. 

In the opening above the tunnel the vein exposed at the back and 
on the sides of the opening consists in the main of the same coarse-grained 
hornblende-epidote filling as elsewhere; but in addition there is present 
much garnet. Near the hanging-wall are several distinct veins of epi- 
dote cutting the vein-mass, and between these and the wall the usual 
vein matter is replaced by a compact aggregate of garnet, hornblende, 
feldspar and calcite, in which the hornblende appears to be the oldest 
component. 

A slide made across the contact of a small epidote vein and the coarse 
hornblende mass shows the hornblende mass to consist of a fine-grained 
mixture of uralite, epidote, quartz, magnetite crystals, calcite nests, 
and veins and lenses of quartz mosaic. The hornblende, however, 
frequently polarizes uniformly over large areas, and produces the coarse 
texture noticed in the hand specimen. 

The epidote vein is a granular aggregate of yellow-green epidote 
crossed by veinlets of quartz mosaic between the grains of which in places 
is a filling of calcite. There is no sharp contact between the epidote 
vein and the hornblende mass. In some places there is a thin seam of 
quartz between the two; but in most places the contact is simply a plane 
on one sid? of which there is an abundance of amphibole and on the 
other side none. 

Toward the center of the vein, but distributed rather irregularly 
through it, are masses of lean ore consisting of a granular aggregate of 
magnetite, hornblende and epidote and masses of what was originally 
a coarse pegmatite but which now is a very coarse aggregate of horn¬ 
blende and epidote, with hornblende individuals often half an inch long, 
containing numerous tiny grains of magnetite. Here and there a garnet 
is associated with the epidote and scattered through the mass are tiny 
veins of calcite. Calcite is especially noted on joint cracks, but it oc¬ 
curs also scattered among the epidote grains. Quartz lenses a few inches 
long are not uncommon in the midst of the hornblende. Near them 
are often little pyrite cubes. In certain portions of the vein the mag¬ 
netite grains in the hornblende become larger. They group into little 
aggregates of lenses and the mass becomes a lean ore. Through this 
calcite veins run in all directions. 

Sections from an irregular mass of epidote and hornblende taken 
from about the center of the vein when viewed under the microscope 


112 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

show large masses of pure epidote, cut by veinlets of quartz and epidote 
and surrounded by a mixture of epidote, hornblende, quartz, and feld¬ 
spar containing little nests of calcite. A few little crystals of magnetite 
are scattered through the hornblende-epidote mixture and a thin border 
of garnet in a few places lies between the large epidote areas and those 
characterized by the presence of hornblende. Quartz veins and epidote 
veins cut through the rock in various directions. The areas in which 
epidote alone, or epidote and calcite occur and those in which hornblende 
is prominent, are so distributed as to suggest that the former represent 
feldspar and the latter pyroxene. Thus reconstructed, the rock appears 
to have been a coarse augite-syenite—probably a pegmatite. 

Lean ore masses scattered through the vein are composed mainly 
of uralite, epidote, and magnetite. The uralite and epidote are in areas 
that suggest a granitic rock. The only differentiation observable in it 
is that in some areas the light colored granular epidote is free from 
hornblende and in others one-half or more of the mass consists of 
crystalloids of hornblende inclosing grains of epidote, feldspar, and 
calcite. The magnetite is in much smaller quantity than would be 
thought from a study of the hand specimen alone. It occurs in a few 
irregular grains surrounded by narrow zones of light colored epidote, 
even when present in areas characterized by abundant uralite. 

Firmstone opening 

Another opening, the Firmstone opening, at the base of the moun¬ 
tain, about 1,300 feet northwest of Smoky No. 2, is an old pit on the 
dump of which are many large fragments which show that the condi¬ 
tions in the vein at this point are the same as at Smoky No. 1 and Smoky 
No. 2. The vein does not change in its character through this length 
of half a mile. 

Mine opening 

Naturally, the best exposures on the Cranberry property are at the 
mine, where there is a large open cut on the east slope of Cranberry Hill 
(Plate XVI), an eastern spur of Hump Mountain, and a tunnel at its 
base. The mine is entered by the tunnel, which runs southwest to the 
vein, at an elevation of 3,211 above sea level. From the junction the 
vein is followed along its strike, which is N. 34° W., and the mixed ore 
and rock are taken out as the advance progresses. Above this level 
are others which were abandoned as the ore was removed. The ore 
is now being worked upward and downward from the tunnel level and 
this at the same time is being advanced along the vein by stoping at its 
end. From the southeast part of the mine a slice of mixed ore and rock 
has been removed which was about 200 feet thick, 800 feet long, and 
SCO feet high (measured on its dip). As the work advanced along the 
strike of the vein the ore body alternately widened and narrowed. It 


PLATE XVIII. 




(B) 


(A) Part of wall of open cut, Cranberry mine, Cranberry, N. C., showing irre¬ 
gular distribution of pegmatite in the vein-tilling. 

( B ) General view of wall of same cut, showing hanging-wall of foliated Cran¬ 
berry granite. 






114 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

also widened and narrowed on the dip. In other words, that portion 
of the vein that is minable occurs in lenses surrounded by portions that 
are not minable under present conditions. (Compare Plate XVII, B .) 
These non-minable portions contain magnetite, but not in sufficient 
quantity to pay for working. If an efficient concentrating process 
were available it is probable that much more rock might be removed 
from the vein and treated with profit, and it is possible that the entire 
contents of the vein might become available for concentration, in which 
case the lens-like character of the ore body might not be so distinct. 

The portions of the vein that are now minable are certainly lenti¬ 
cular. (See plat, Plate XVI.) The lenses are about 800 feet long and 
200 feet wide at their widest part. Their heights in the plane of the 
dip are not known but are in the neighborhood of 500 feet. So far as 
present observations are possible the lenses appear to have no pitch. 
They are separated from one another partly by pinches in the vein 
but more commonly by the narrowing of the richer portion of the vein¬ 
filling. However, they are connected by thin stringers of ore, which 
in every case thus far noted, lead from lens to lens. This is true not 
only for that portion of the vein in the neighborhood of Cranberry, but 
apparently it is true also for its northwestern extension as far as Shell 
Creek. Mr. Hamilton, who has investigated this portion of the vein 
by magnetic methods, states that a narrow line of attraction can be 
detected following the course of the vein and that at irregularly spaced 
intervals this line expands to broader areas. In the areas of most pro¬ 
nounced attraction are the Cooper, Wilder, Red Rock, Patrick, Tee- 
garden, and Ellis explorations. 

Explorations in the mine have not shown the downward termination 
of the lenses nor have they outlined their limits in all other directions. 
The mine plat (Plate XVI) shows that the general shapes of the hori¬ 
zontal sections of the ore-bodies are those of horizontal sections of lenses, 
but no complete vertical sections are available. The floor of the lower 
level of the mine is on ore, but drill holes that were sent downward to 
determine the extension of the ore-bodies down the dip are reported to 
have shown very little ore in this direction. It is reasonably certain 
that the ore occurs in lenses and that the lenses do not terminate ab¬ 
ruptly with depth. If the source of the ore was, as supposed, a sub¬ 
terranean magma (see page 68), it is probable that the deposits extend 
downward for some distance. On this assumption there should be ore 
below the present floor of the mine. It is upon this supposition that the 
estimate of reserves given on page 78 is based. 

The best exposures of the vein are in the large open cut on the slope 
of the hill. (See Plate VIII, A, Plate XVII, B , and Plate XVIII.) 
The vein here is about 80 feet wide. On the walls of the cut are excellent 
exhibitions of the relations of the various phases of the vein-filling to 
one another that have already been described (pages 4 3 to 67.) 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


1 15 

Large “horses" of rock occur in the vein, and on the wall of the 
cut sections of some of them can he seen. Some of the specimens on 
the dumps are not very different in appearance from those taken from 
exposures of the Cranberry granite. They are so like the schistose 
portions of the Cranberry granite that they are believed to be splinters 
of the granite mass that were split off the main mass at the time the 
vein was formed. Other specimens of schistose granites are streaked 
porphyritic gneisses with here and there alternating layers of darkgreen 
hornblende like that associated with the ore. These were apparently a 
part of the vein-filling. They consist of zoisitized plagioclase fragments 
in a schistose matrix composed of small fragments of plagioclase, elon¬ 
gate grains of newly crystallized, striated and unstriated feldspars, a 
little quartz, some uralite, considerable granular colorless epidote and 
a few streaks of yellow-green epidote. (Plate XX, B.) Nests of calcite 
are scattered through the matrix irregularly. The hornblende flakes 
and epidote streaks wind sinuously between the large feldspar fragments 
and are separated from one another by a fine-grained mosaic of quartz 
or of quartz and feldspar. Much of the colorless epidote is in tiny grains 
and crystals scattered through the feldspar, but in some places the epi¬ 
dote particles are arranged in thin straight lines following definite 
twinning striae as though certain of the plagioclase lamellae had been 
more susceptible to change than others. 

The general features of the rocks constituting the vein-filling have 
already been described (see page 48), but there are certain additional 
features exhibited by some of the specimens in the rock pile at the bot¬ 
tom of the incline that should be referred to briefly. One of the more 
abundant rocks in the pile is a coarse-grained hornblende pegmatite 
cutting a coarse hornblende rock. In most specimens this has the char¬ 
acter already described (page 62), but in some specimens magnetite 
occurs abundantly as irregular masses in the hornblende. Where not 
scattered indiscriminately through the hornblende in the pegmatite it 
appears as a selvage between the pegmatite and the coarse hornblende 
rock through which the pegmatite cuts. The hornblende rock also often 
contains little blebs of magnetite and is traversed by veinlets of the 
same mineral. 

A few fragments of pegmatite are essentially magnetite pegmatites. 
They differ from the more common hornblende pegmatites solely in the 
fact that magnetite has replaced most of the hornblende. The micro¬ 
scope shows that there still remains considerable hornblende in the black 
masses within the pegmatite but it is so completely saturated with mag¬ 
netite, that the hand-specimen appears to consist exclusively of partly 
epidotized feldspar and magnetite. There is no magnetite present, 
however, except in aggregates with hornblende. It is not present in the 
feldspar unmixed with hornblende. 


116 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

In many specimens the proportion of magnetite in the pegmatite 
is so great that the mass becomes ore. In these the feldspar is limited 
to a few ill defined crystals mixed with coarse hornblende crystalloids 
and a few little elongate grains of the same mineral forming lenses em¬ 
bedded in an irregular, more or less schistose aggregate of hornblende 
and magnetite, traversed by numerous veinlets of magnetite. 

In a characteristic thin section are large plagioclase fragments 
crushed on their edges to small fragments which are mingled with grains 
of epidote and wisps of amphibole to form a matrix in which the large 
fragments are usually embedded. Often the large fragments are cracked 
and their parts slightly displaced, their twinning striations at the same 
time being bent and twisted in a complicated way. Between the frag¬ 
ments of the feldspar is a mixture of small quartz grains and epidote, 
the latter of which is not only present in small equidimensional grains 
but also in elongate grains and in large clusters of grains. The quartz 
grains are slightly lenticular. Their long axes are approximately parallel 
to the elongation of the epidote and to that of the hornblende, and as 
a result the rock is schistose. The epidote and much of the quartz 
are secondary as they both form little veins in the feldspar and some of 
the more compact hornblende. A little of the quartz is probably original. 
This is now represented by a few grains a little larger than the average 
that exhibit shadow extinction. Crystals and groups of crvstals of 
epidote are also scattered through the feldspars, and veinlets of the same 
mineral occur in the cracks between their dissevered parts. Between 
neighboring large grains are often thin seams of amphibole inclosing in 
places large nests of bright-yellow epidote. 

In the richly magnetitic pegmatites the magnetite is commonly 
associated with the hornblende. It is present either as comparatively 
large masses comparable in size with the feldspars and pyroxenes before 
they were broken, or as smaller sharp-edged pieces scattered through the 
aggregate of uralite, quartz, feldspar and epidote that lies between the 
large broken grains. In many places the sharp-edged pieces appear to 
be fragments of large grains that have been moved apart for considerable 
distances. In other places they are so close that they can be fitted 
together into a single grain. Where close together they are separated 
from one anottier iiy nairow cracks, in which may be a little brown 
biotite or a little uralite. d he larger pieces have irregular boundaries 
as though they had been corroded, and it is noticeable that any feldspar 
in contact with them has been completely changed to epidote. In some 
sections are also a few crystals of apatite. 

Allanite is the only other mineral that has been seen in any section 
of pegmatite. It is in crystals several millimeters in length, that seem 
to have suffered no deformation and but very slight alteration. 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


117 


Where the feldspar of any variety of the pegmatite is in contact 
with masses of hornblende, the feldspar near the contact is commonly 
completely changed to epidote whereas that an inch or more from the 
contact is white and fresh and shows no trace of epidotization. The 
epidotizing solutions appear to have emananted from the hornblende, 
which may indicate that the hornblende was intruded after the peg¬ 
matite. 

Most fragments of the pegmatite on the dump are of the kind de¬ 
scribed. There are, however, others of a very quartzose type, in which 
the quartz is blue. This variety contains no hornblende, but is composed 
of quartz and feldspar almost exclusively. As the rock shows very little 
schistosity and its components show no evidence of crushing, it must 
be a much younger rock than the more common syenitic pegmatite. 
(Compare Plate VIII, B.) 

The garnet rock that occurs so abundantly in Smoky No. 2 (page 110), 
is fairly abundant on the dump of the mine. In part it is associated 
with hornblende and in part with magnetite. In the mine it is said to 
be always close to pegmatite, but the exact relations of the two are not 
more definitely known. Whether associated with hornblende or magne¬ 
tite the garnet makes up by far the greater part of the mass. As a little 
feldspar and epidote are present in all specimens of the garnet rock it is 
probable that the rock is either a part of the pegmatite or a contact 
metamorphic product of some pre-existing rock. 

The hanging-wall rock in the mine is a chloritic gneiss cut by a few 
quartz veins. (Plate XVIII, B.) It is apparently a very much sheared 
phase of one of the darker layers of the Cranberry granite. An analysis 
by Dr. J. I. D. Hinds of the Tennessee Geological Survey yielded: 


Partial analysis of gouge in hanging-wall of vein at Cranberry mine. Cranberry, N. C. 


Silica (SiO>). 58.46 

Alumina (AI 2 O 3 ) . 19.52 

Ferric oxide (FeiOs).) 


Ferrous oxide (FeO) 


Magnesia (MgO). 3.10 

Lime (CaO). .96 

Phosphorus pentoxide (P 2 O 5 ) .... .47 

Water (H 2 0+). 2.78 


OTHER OPENINGS IN THE CRANBERRY BELT 
Lee Johnson place 

That portion of the Cranberry belt between Vale and the south- 
easternmost opening of the Cranberry mine near the crest of Smoky, or 
Little Fork, Mountain has been traced only in a very general way. 
There are two openings on the Lee Johnson place on the west side of 
the road, one mile north of Vale, and occasional small openings or out¬ 
crops on the northeast s’ope of the mountain, but most of the course of 
the vein is covered by such a thick forest growth that it cannot be fol¬ 
lowed. At the Johnson place are two openings, one a pit and the other 









118 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

a tunnel. At present both openings are overgrown and all that is vis¬ 
ible at them are their dumps. The ore was like the rich ore at Cranberry. 
The Interstate Coal and Iron Co. is said to have shipped from them 
about 2 carloads. It is reported that the vein strikes NW. and that 
its dip is 25° to 36° SW. 

Cooper place 

The first openings on the vein northwest of the Cranberry mine 
are at the old Cooper place about three-quarters of a mile south of Elk 
Park. At present nothing can be seen of the mine but several large 
depressions which represent the old open cuts. Nitze 75 states that the 
openings were made about 1884 and that a small quantity of ore was 
shipped from them to Roanoke, Va. He declares that they exposed “a 
body of ore, and mixed ore and gangue varying in thickness, as visible 
at present near the outcrop, from 5 to 10 feet, with a dip of about 33° 
southwest.. Southwest of the Cooper openings is a series of shallow 
pits on the northeast slope of Hump Mountain, but they show nothing. 
Perhaps these openings are on the Crowder place which is described by 
Nitze as being 1 mile S. 30° W. from Elk Park. On the western slope 
of a ridge, near its summit, writes Nitze, 

“the outcrop was stripped for a short distance, exhibiting a backbone of ore 
from 1 to 2 feet in thickness; it was explored 15 feet below the surface by a 
short adit-level and found to widen to 3 or 4 feet. A shaft was sunk on the 
ore, at the mouth of this adit-level, to the depth of 40 feet, proving in increase 
of thickness. . . . 

“The ore resembles that of the Cranberry mine in every particular. 

The strike is northwest . . and the dip nearly vertical.” 

Ellers and Hardigraves Elk Park openings 

It is possible that Nitze’s last reference is to the openings about 
three-quarters of a mile southwest of Elk Park. These are known as 
the Ellers and the Hardigraves Elk Park openings. They are on oppo¬ 
site sides of one of the branches of that fork of Elk Creek which crosses 
the railroad just west of Elk Park station. It is reported that they have 
yielded about 3,000 tons of ore averaging about 42 per cent, iron and 
0.012 per cent, phosphorus. 

On the Ellers property there are three openings, of which one is a 
shaft. Although some work was being done at the shaft at the time of 
the writer’s visit in 1019, no rocks were exposed. The miners stated 
that the vein is 4 to 4j^ feet thick, possibly increasing to O}^ feet with 
depth. At the Hardigraves openings the vein rolls with a general south¬ 
west dip. As the walls have become covered with soil and weeds noth¬ 
ing of interest with reference to the ore could be seen here. However, 
a great vein of weathered pegmatite was recognized; but whether it cut 
the ore or not could not be determined. 


75 Op. cit., p. 180. 




MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


119 


Small openings and surface exposures leave little doubt that an ore 
belt continues without serious interruption from Cranberry to Elk Park, 
and magnetic observations seem to indicate that if breaks do occur in 
the vein they are of such slight magnitude as to be of no significance. 
They may indicate merely that the ore is in lenses in the vein and not 
in a continuous sheet. 


Wilder mine 

The next openings to the northwest of the Elk Ridge mines are 
those of the Wilder mine, in Carter County, Tennessee, about one-third 
of a mile south of the railroad and half-way between Elk Ridge and 
Shell Creek stations. This mine is about 2 miles north of west of the 
Ellers mine. The Wilder mine was first opened before 1880, but was 
worked only on a small scale. It was taken over by Milt Miller and 
associates in 1896 and about 5,000 tons of lean ore was shipped to the 
Cranberry Furnace Co. at Johnson City. The last shipment (in July, 
1918) was 10 cars of ore averaging 30.70 per cent of iron and 0.014 per 
cent of phosphorus. The average iron content of 4,915 tons shipped 
to the Cranberry furnace was reported by Mr. E. B. Kirby to be 37.5 per¬ 
cent and that of titanium oxide 0.15 per cent. 76 The mine is now owned 
by the Cranberry Furnace Co. The mine consists of several large open 
pits, several tunnels and underground drifts and a number of smaller 
openings that are distributed in a bewildering way (Plate XIX), until 
it is realized that the vein here is in folds. The country rock is Cran¬ 
berry granite. 

At the mouth of the large tunnel at the east end of the property 
the dips are about 20° toward the southwest and 100 feet farther south¬ 
west at the mouth of a smaller opening the dips range between 15° 
and 40° to the northeast. Again, at the northwest end of the large 
cut in the western part of the property the dip is 45° southwest and at 
the opening about 150 feet southwest of the east end of the cut is about 
10° northeast. About 400 feet northwest of this point a flat dip is again 
observed. Observations are so few that they do not furnish sufficient 
data for working out the structure of the vein in detail. They indicate, 
however, that the two parallel deposits at this place are not in different 
veins but in the same one that lies in a synclinal fold, with its axis be¬ 
tween the two lines of deposits. 

The vein-matter is very much like that at Cranberry. The major 
part consists of layers of interbanded hornblende and epidote alternating 
with layers of coarse hornblende. The epidote grades into pegmatite 
which clearly is intrusive into the hornblende, giving an impregnation 
gneiss. 

A section of a very evenly banded gneiss reveals wide layers of 
coarsely granular hornblende, very narrow layers composed of alter- 


76 Quoted by S. H. Hamilton in an unpublished report to the Tennessee Geol. Survey 




120 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

nating layers of hornblende and epidote and slightly thicker ones of 
epidote, all evenly interbanded, as though the rock were an impregna¬ 
tion gneiss in which the feldspar had been changed to epidote. There 
are also a few narrow belts of fine-grained granular epidote alternating 
with bands of quartz mosaic containing a little uralite. Some of the 
quartz is in small lenses, and some in narrow seams or veins cutting 
through the epidote. 

An analysis by Dr. J. I. D. Hinds, chemist of the Tennessee Geo¬ 
logical Survey, of a specimen of a coarse-grained hornblende rock col¬ 
lected by Mr. Hamilton to represent the vein filling resulted as follows: 


Partial analysis of vein-filling at Wilder mine, N. C. 


Silica (SitL). 

. 46.22 

Magnesia (MgO). 

. 2.92 

Alumina (AI2O3) . 

. 5.44 

Water (II oO). 

. .40 

Iron oxides (as Fe^Os). 

. 27.52 



Lime (Ca9). 

. 16.00 


98.50 


A magnetometric survey made by Mr. Hamilton 77 indicated that 
on the east side of the little branch dividing the property into two parts 
a buried magnetic mass occupies about 210,000 square feet. (See 
Plate XIX.) It dips to the south and pitches to the east. If the ore- 
bodv is 5 feet thick, according to Hamilton it contains 100,000 tons of 
ore. To the west of the branch another ore-body is indicated, but it is 
broken at several places and contains only 50,000 tons of ore. If the 
ore-bodies are more than 5 feet thick, the quantity of ore in them is 
correspondingly larger. In the two bodies Hamilton estimates 150,000 
tons of ore as probable and 600,000 tons as possible. Hamilton does not 
make any statement of the quality of this ore, but from the context in 
his report it is probable that the estimate is based on a content of iron 
averaging 25 per cent. 

In order to determine the availability of the ore for concentrating 
he obtained 2 cubic feet of rock from the Maxwell tunnel (Plate XIX), 
on the east side of the creek, and crushed it to pass a five-eighths inch 
mesh. The material that passed a three-sixteenth inch mesh was screened 
out, and both coarse and fine screenings were passed over a Firmstone- 
lype magnet actuated by a current of 13 amperes. A crude ore contain¬ 
ing 25.08 per cent, iron, crushed to five-eighths, passed over a magnet 
carrying 13 amperes of current yielded a concentrate of 28.4 per cent, 
of iron, after retreating the tails four times. One-third of the total iron 
was lost. The smaller size screenings subject to the same treatment 
yielded a concentrate containing 28.3 per cent iron, but only one-fourth 
of the total iron was lost. When crushed to one-twelfth inch mesh and 
subjected to a magnet of the same strength in water a concentrate of 
45.25 per cent iron was obtained, but no estimate was made of the quan¬ 
tity of total iron that was lost. Hamilton concludes that the ore of the 


77 Hamilton, S. H., Unpublished report to the Tennessee Geol. Survey. 










PLATE XIX. 



Isodynamic chart of Wilder mins property, near Shell Cree't, Carter County, 
Tenn. (By S. H. Hamilton. Courtesy of Cranberry Furnace Co.) 





































122 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Wilder mine is valueless unless subjected to fine grinding and concen¬ 
tration. 

Greenlee and Ray and Tester property 

Higher on the hill and west of the Wilder mine are several open 
cuts and underground workings in which the ore is similar to that at 
the Wilder mine. Some ore was taken from them but it was shipped 
with the Wilder ore. Mr. Hamilton states that his survey showed no 
magnetic line going down the hill into the Morgan Branch hollow to 
the west. 

Red Rock mine 

• 

About half a mile west of the Wilder mine is the Red Rock mine, 
which is well up on a steep slope on the west side of Morgan Branch 
hollow and about half a mile south of the East Tennessee and Western 
North Carolina Railroad. The property is owned by the Tennessee 
Coal, Iron and Railway Co. It was leased to Steven Pittman who mined 
a little ore and then abandoned it. The place is now so overgrown that 
it is impossible to learn much about the relation of the ore to the country 
rock. On the dump, however, are great fragments of a rock composed 
of garnet, magnetite, epidote, calcite, and quartz and also large pieces 
of a coarse pegmatite. Aside from the pegmatite the two most promi¬ 
nent rocks on the dump are a massive granular aggregate of garnet, 
hornblende and epidote and an equally massive aggregate of hornblende 
and epidote. 

In the garnetiferous. rock the garnet and hornblende form a rock 
without any trace of schistositv. In it are irregular lens-like masses 
of coarse hornblende and calcite and in this aggregate are nests of al¬ 
most pure marble. Under the microscope the rock is seen to be an 
aggregate of anhedrons of garnet and a light green pyroxene which is 
uralitized in patches and saturated with calcite. Calcite occurs also as 
little nests in the uralite and in tiny veins crossing the partially uralitized 
py roxene. The same mineral is also in large grains in corners between 
the other components and as enclosures in the garnets. Much of the 
calcite appears to be a result of the decomposition of the pyroxene, as it 
is more abundant in the more completely uralitized pyroxene grains 
than in those that have suffered little uralitization. Whether the large 
grains of calcite in the garnets and in the spaces between the garnets 
and the pyroxenes are original or secondary has not been learned. 

On analysis the garnets carefully separated from the other rock 
components gave to Dr. J. I. D. Hinds, chemist of the Tennessee Geo¬ 
logical Survey, the following result: 

Analysis of garnet separated from the vein-filling at the Red Rock mine, Tenn. 

Silica (SiCh). 36.64 Ferrous oxide (FeO). 5.14 

Alumina (A1>0 3 ) . 8.45 Lime (CaO). 29.20 

Ferric oxide (Fej0 3 ). 20.52 


99.95 








MINES ANI) PROSPECTS IN SILICEOUS MAGNETITES 


123 

1 lie epidote-hornblende rock in thin section is seen to be very 
slightly schistose. Masses of granular epidote, a few irregular dark gar¬ 
nets, mixtures of uralite and epidote, little remnants of twinned plagio- 
clase in the midst of the epidote, small irregular quartzes scattered 
through the other components, and forming mosaic veins cutting through 
them, and little nests of calcite in the mixtures of uralite and epidote 
make up the rock. The masses of granular epidote, with some quartz 
grains and remnants of feldspar scattered through them, may represent 
original feldspar; the mixtures of uralite, epidote, quartz, and calcite 
may represent augite. If this is so the original rock was an augite 
syenite. The garnet is in streaks between the epidote areas and those 
in which hornblende and epidote are both present and in coronas sur¬ 
rounding the epidote. It occupies the position of a contact product 
between the inferred original augite and feldspar. 

The ore here is different from that of the other mines in the vicinity, 
in that it contains a great deal of calcite. In another place (page 195), 
are outlined the reasons for supposing that this difference may be due 
to the fact that in the mine the ore-bearing solutions encountered lime¬ 
stone rather than granite in their ascent. 

Patrick mine 

About three-quarters of a mile farther northwest are the old open¬ 
ings of the Patrick mine on the south side of the road running south 
along Shell Creek, and between this and the Red Rock mine are other 
old openings in which now practically nothing of interest can be seen. 
They are of importance at present only as indicating that the vein belt 
is continuous between the two mines. 

At the Patrick mine are holes in the hill slope alongside the road 
and there is an outcrop in the road, but the relations of ore to vein-rock 
and of vein-rock to eountrv rock are the same as at the Cranberry mine, 
so far as can be observed. A little ore is said to have been produced 
tw'entv or thirty years ago, but the place has been abandoned. 

Teegarden and Ellis mines 

Farther to the northwest are two comparatively new mines about 
half a mile apart on opposite sides of a little ridge, about three-quarters 
of a mile southeast of Shell Creek station on the road up Shell Creek. 
The strike of the vein at the eastern mine is N. 60° W. and its dip about 
30° SW. The eastern mine, in Vance hollow, is knowm as the Teegarden 
or Shell Creek mine, and the western one, in Ellis hollow, the Ellis mine 
or Oakes Entry. The mines were worked by Messrs. Ellis and Kirk¬ 
patrick in 1917, producing about 500 tons of ore that w r as taken by the 
Cranberry furnace. In December, 1917, the Cranberry Furnace Co. 


124 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

leased the property and operated the Teegarden mine until the end of 
May, 1919. The Ellis mine was worked mainly as a prospect. Both 
mines are now idle. 

During the two years of operation there were shipped from the pro¬ 
perty 17,375 tons of ore, averaging 36.36 per cent iron and 0.0113 per 
cent phosphorus. It was fed to the furnace without beneficiation. As 
mining progressed the quality of the ore deteriorated to such an extent 
that it was no longer acceptable at the furnace and shipments were 
stopped. Between May and September, 1917, the average content of 
the ore shipped was 43 63 per cent iron and 0.0093 per cent phosphorus, 
and between January and May, 1919, the average iron content was 32.10 
per cent and the average phosphorus 0.014 per cent. 

At the Teegarden mine it is said that there was a streak of rich mag¬ 
netite 5 feet or 6 feet w T ide in a lean ore vein 20 feet wide. Judging by 
the material on the dump the vein is a duplicate of that at Cranberry. 
Pegmatite cuts the vein and the ore-body, which pinches at intervals, 
in consequence of rolls in the hanging-wall. The pegmatite that crosses 
the ore extends beyond the vein walls into the surrounding Cranberry 
granite, cutting it at an inclination to its foliation. (Plate VIII, B.) 
However, it is, itself, more or less schistose in the same direction as the 
foliation of the gneiss surrounding it, suggesting that it may have been 
forced between the gneiss layers while schistosity was being imposed 
on the mass. The pegmatite is a quartzose variety containing much 
blue quartz. It is in every respect like the quartzose pegmatite at the 
Cranberry mine. 

On the dump of the mine are all phases of the epidote-hornblende 
rocks noted in the description of the Cranberry mine. Moreover there 
are a few specimens of nearly pure hornblendite consisting of layers of a 
fine-grained slightly schistose hornblende rock in which there is a little 
feldspar and much magnetite, others of a coarse-grained hornblende 
rock exhibiting neither schistosity, nor the presence of feldspar or of 
any other component than hornblende, and others of a light-gray gneiss 
that is reported to occur as a “horse” in the vein. 

The light-gray gneiss is a crushed mass of orthoelase and striated 
acid plagioclase, wisps of amphibole and a few grains of colorless epidote. 
Large fragments of the feldspars are embedded in a finer grained schistose 
feldspar-quartz matrix in which are many little nests of calcite, shreds 
of green amphibole, a few shreds of biotite and a comparatively few 
small grains of epidote. The fragments of this matrix are cemented by 
a still finer grained aggregate of the same composition. All of the larger 
pieces of the matrix have their longer dimensions in parallel orientation, 
and the shreds of amphibole are arranged in the same general direction, 
though they are much bent as they curve around the large fragments of 
feldspar. It is probable that the gneiss is a part of the Cranberry granite. 
It certainly is not a part of the vein material. 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


.25 


The fine-grained hornblende layers are lean ores and their schistosity 
is due primarily to the presence of the magnetite in parallel streaks. All 
their components are elongated in the same direction as the layer¬ 
ing noticed in the hand specimen, thus accentuating the schistosity pro¬ 
duced by the concentration of the magnetite in definite layers. The 
magnetite is in long, thin ragged pieces, many of which appear to be frac¬ 
tured and in small grains which in most cases look as though they had 
been broken from the larger ones. The mass in which the magnetite 
is embedded is a very schistose mixture of uralitic hornblende, wisps of 
brownish-green biotite, calcite, a little quartz and small particles of 
magnetite. The quartz and some of the calcite are in veins that extend 
in the direction of the rock's schistosity, and in the section studied the 
calcite veins are in the layers in which the magnetite is most thickly 
concentrated. Calcite is also scattered throughout the entire section, 
but it is much more abundant and in much larger pieces in the layers in 
which magnetite is also most abundant. Uralitic hornblende constitutes 
the principal component of the coarse-grained layers between the richly 
magnetic layers. Its fibers are all elongated in the same direction. As¬ 
sociated with them are a few wisps of biotite, and in the spaces between 
these are little nests of calcite. Scattered through this mass are small 
grains of magnetite, which are in nearly all cases arranged roughly in 
lines. The biotite is the only component that is not in all cases oriented 
with the schistosity. Although most of the wisps of biotite that are em¬ 
bedded in the hornblende lie parallel with the hornblende fibers, many 
others cross them nearly perpendicularly; and the wisps that penetrate 
the calcite are arranged radially, in some cases forming radial groups. 
The biotite is evidently the youngest mineral in the rock as its spicules 
cross indifferently the borders between hornblende grains and calcite 
grains. They were evidently not present when the schistosity was 
produced. 

Where epidote veins cut the lean ore, the epidote is bordered con¬ 
centrically by thin selvages of hornblende, layers of nearly pure magne¬ 
tite, and layers of mixed magnetite and hornblende. 

Pegmatite fragments on the dump are often garnetiferous, and one 
specimen shows a mixture of sugary marble and light red garnet with 
the pegmatite. The relations of the two rocks could not be determined. 

A selected specimen of the lean ore, analyzed by Dr. J. I. D. Hinds, 
of the Tennessee Geological Survey, gave: 


Analysis of lean ore from the Teegarden mine, near Shell Creek, Tenn. 


Silica (Si0 2 ). 22.05 Lime (CaO). 

Alumina (A1 2 0 3 ) . 0.48 Phosphorus pentoxide (P 2 0 6 ) . . . . 

Ferric oxide (Fe 2 0 3 ). 19.30 Titanic dioxide (Ti0 2 ). 

Magnetite (Fe 3 0 4 ) . 37.4G Carbon dioxide (C0 2 ). . 

Magnesia (MgO). 0.00 Mater. 


10.24 
0 . 10 
0.00 
2.70 
0.28 

99.90 












126 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

At the Ellis mine the vein is said to be 10 feet wide. Its strike is 
about 10° to 15° north of west, but it varies slightly. The dip is south¬ 
erly, as high as 45° in places. The vein rock is much shattered. Large 
coarse hornblende masses are cut by quartz veins and by a few streaks 
of pure magnetite. 

A magnetometric reconnaissance of the country between the Tee- 
garden and the Ellis mines showed a continuous magnetic line between 
them. 78 A short distance east of the Teegarden opening is a pinch 
in the vein extending for 100 feet. Beyond this to the eastward another 
lens is indicated, and beyond this another larger ore-body that is folded. 
Below the present level of the mine and farther west another ore-body 
300 feet long is to be expected. However, none of the ore-bodies are 
large, and Hamilton’s estimate of the probable ore that might be reached 
bv the two mines is 250,000 tons. 

Heupscup Ridge prospects 

Heupscup Ridge is the spur of Big Yellow Mountain extending 
northward between Shell Creek and Hampton Creek. On the east slope 
of the ridge are a few outcrops and several prospect holes that mark the 

westward course of the vein through the Teegarden and Ellis mines. 

* 

On the west slope of the ridge, near Hampton Creek, a cut was run into 
the hillside years ago by a Mr. Young. Although the cut is now so 
overgrown that no rock can be seen in its walls, from the size of the 
opening it is safe to infer that some ore was obtained. 

The rock exposures on the road between the mines and Shell Creek 
are of a light-gray granite, presumably Cranberry, which is coarse and 
gneissic in some places and finer and banded in others. No schists were 
associated with either type of the granite, but it is streaked in places 
with pegmatite. 


Peg Leg and Old Forge mines 

On the divide between Hampton Creek and Doe River are the open¬ 
ings of the Peg Leg mine which has been worked intermittently since 
colonial days. As late as 1885 ore was taken from the surface to supply 
the Doe River forge on the banks of Doe River. In 1898 the place was 
reopened by the Crab Orchard Iron Co. and about 1,000 tons of ore 
was shipped. It was then again closed and remained idle until 1917 
when it was prospected by the Magnetic Iron & Coal Co., without sa¬ 
tisfactory results. A cut was driven 600 feet in an easterly direction 
through a vein 50 feet wide, of which about a third was lean ore. An 
analysis of a sample of the ore by Dr. J. I. D. Hinds resulted as below: 


78 Hamilton, S. H., Unpublished report to Tennessee Geol. Survey. 





MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


127 


Analysis of sample of lean ore from northeast end of the Peg Leg prospect, Carter County, 


Ten 

Silica (SiO>). 23.52 

Alumina (A1 2 0 3 ). 60 

Ferric oxide (Feo0 3 ).^ 

Ferrous oxide (FeO). j 1,5 

Manganese oxide (MuO). 0.00 

Lime (CaO). 7.20 


essee. 


Magnesia (MgO). Tr. 

Barium oxide (BaO). 21 

Soda (Na 2 0) . 1.12 

Potash (K 2 0). Tr. 

Phosphorus (P). Tr. 


98.80 


Mr. E. B. Kirby in a report 79 on the iron resources of the Doe River 
valley states that the east cut of the Peg Leg mine shows ore averaging 
83.8 per cent of iron through a distance of 150 feet along the vein, and 
that it may be broken in faces 10 to 17 feet wide. 

At the opening made in 1917, which is about one mile south of Roan 
Mountain station on the road up Doe River, is a large dump of fresh 
rock on which nearly all the varieties of rock seen at Cranberry may be 
recognized. The ore fragments show a very rich, coarse magnetite like 
that of the later ore at Cranberry. The ore, as seen under the microscope 
is very much like that at the Kirby place. (Plate II, B and page 52). 
It consists mainly of green pyroxene and magnetite, the former in large 
anhedrons that often possess smooth curved boundaries. They are 
slightly pleochroic in yellowish-green and pure-green tints and are 
crossed by numerous cleavage cracks, by the diallage parting, and by 
many irregular fractures that are filled by quartz and calcite. The 
magnetite is in irregular masses between the pyroxene grains, and often 
surrounding several. Where magnetite is absent as the filling of the 
interstitial spaces between the pyroxene grains, its place is taken by 
quartz, or by quartz and calcite, with a few fibers or wisps of uralite. 
In the narrowest spaces between the pyroxene a thin filling of uralite or 
of calcite may exist alone. Moreover, where a pyroxene is in contact 
with the quartz-calcite filling the pyroxene is bordered by uralite and 
in some cases uralite spicules extend entirely across the space occupied 
by the filling. Here and there are large grains of epidote, but they are 
rare. The same mineral occurs also as little veins in the magnetite. 
The filling appears to be secondary. 

The Old Forge openings are about 500 feet from the west bank of 
Doe River, nearly opposite the Peg Leg mine. The place is now over¬ 
grown, but Hamilton states 80 , that old pits and float ore are so distrib¬ 
uted as to indicate a vein about 100 feet wide. Mr. Kirby in the report 
already referred to, says that on the west side of the river the ore appears 
in two streaks and 5 feet wide. In the first streak the total iron 

content of the ore determined was 39.98 per cent and the quantity of 

_ 

^Quoted by S. H. Hamilton, through courtesy of Mr. M. F. Miller, Erwin, Tenn. 
Unpublished report to Tennessee Geol. Survey. 

soUnpublished report to Tennessee Geol. Survey. 

















128 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

magnetite present 28.86 per cent. In the second streak the total iron 
was 21.30 per cent and the magnetite only 7.73 per cent. Sixteen hun¬ 
dred feet beyond are exposures of “36 per cent ore in a face 16 feet wide,” 
and on the crest of the hill about 1,300 feet farther west is an old shallow 
pit that uncovered a vein 7j^ feet wide. Mr. Kirby believes that len¬ 
ticular ore bodies follow one another along both the strike and the dip 
of the vein, that there need be no fear of the stoppage of the ore, and 
that the magnitude of the available reserves depends solely upon the 
cost of mining and concentration. 

Horse Shoe prospect 

In the little hollows running back into the hill on the west side of 
Doe River at the horse shoe curve are a few exposures of ore and much 
float ore. About half a mile from the river and 600 feet above it the most 
promising exposures have been prospected by several pits and small 
cuts. The country rock which is mapped as Cranberry granite by Keith 
is markedly different from the Cranberry granite farther east. Most 
of it is strongly schistose and very dark. It seems to be very chloritic 
and its feldspathic constituent is crushed and drawn out into lenses. 
It is interlayered with light-colored granite. The impression made by 
the relations of the two rocks is to the effect that the granite had intruded 
a schist series, in some places the granite being in great excess and in 
others the schist being more abundant. Where the granite predomi¬ 
nates the result is an area of granite, streaked in places by schist; where 
the dark schist is in excess there is an area of schists cut by granite. 

At the two large openings examined the vein rock is very dark. It 
is cut by pegmatite, epidote and quartz veins as at Cranberry. More¬ 
over the ore contains much green hornblende. The strike of the vein 
is apparently a little north of west. If this is correct, the vein is probably 
a different one from that on which the Peg Leg deposit is situated. 

Hamilton quotes Kirby as believing that the vein at the Horse Shoe 
openings is a different one from that at the Old Forge prospect. Most 
of the ore was found to be of low grade, but one streak 400 feet long and 
about 8 feet wide assayed 31.9 per cent of iron. 

Kirby’s conclusion is that the available iron ore resources of the 
Doe River valley between the Peg Leg and the Horse Shoe mines aggre¬ 
gate from 180,000 to 270,000 tons but that the veins might yield ore 
indefinitely if it were not necessary to consider the cost of mining. 

In order to learn whether the crude ore of the area would pay to 
concentrate, Kirby made up samples of the ore layers in the Peg Leg, 
Old Forge and Horse Shoe openings, crushed them to 20 inch mesh and 
subjected the pulverized ore to the influence of a magnet. The process 
resulted in a production of 32.5 per cent of a high-grade concentrate 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


129 


and 67.5 per cent of tailings carrying 17.1 per cent of iron. The compo¬ 
sition of the crude ore and of the concentrate is given as below: 

Analyses of crude ore and concentrate from Peg Leg and Old Forge openings. Carter County, 

Tennessee. 



Crude ore 

Concentrate 

Silica (SiOo). 

.... 33.86 

6.54 

Iron (Fe). 

. 33.80 

64.52 

Alumina (ALO 3 ) . 


1.18 

Lime (CaO). 

.... 8.87 

1.26 

Magnesia (MgO). 

4.31 

1.62 

Titanium dioxide (TiO>). 

. . . . .00 


Sulphur (S). 

. 03 


Phosphorus (P) . 

Tr. 

Tr. 


Mr. Kirby declares that a very rich product may be obtained from 
the ore of the Doe River valley, but that as it requires 2.8 tons of the 
crude ore to make 1 ton of concentrate, and the concentrate would have 
to be sintered before charging to the furnace it is doubtful if the operation 
would pay. 

Julian prospect 

About one mile south of the line between the Peg Leg and Horse 
Shoe mines, and therefore about the same distance south of the Cran¬ 
berry vein is a prospect hole on the west side of Shorr Hollow Ridge 
between Heaton Creek and Sugar Hollow. 81 The old dump shows lean 
ore composed mainly of magnetite and epidote. An analysis of a speci¬ 
men by Dr. J. I. D. Hinds, of the Tennessee Geological Survey, gave: 

Partial analysis of specimen of iron ore from Julian land. Carter County, Tennessee. 

Silica (Si0 2 ). 48.20 Lime (CaO). 14.80 

Alumina (AI 0 O 3 ) . 5.03 Magnesia (MgO). 9.78 

Iron (Fe). 15.68 Phosphorus pentoxide (P2O5) .... Tr. 

Campbell prospect 

On the strike of the vein passing through the Peg Leg and Horse 
Shoe mines and about half a mile west of George Creek, prospecting 
was begun over an area in which pieces of exceptionally rich ore had 
been found. A magnetic survey showed attraction over a larger area 
than at the Cranberry mine, and active operations to mine the ore were 
started. However, some of the backers of the project were drowned 
in the Titanic disaster and work was abandoned. The composition of 
the ore, as quoted by Hamilton^, was: 62.6 to 67.0 per cent of metallic 
iron (Fe), 3.25 per cent of silica (SiO,), 0.05 to 0.19 per cent of phosphorus 
(P), and no titanium (Ti). Hamilton states, on the authority of Hon. 
J. C. Campbell, that several thousands of dollars worth of work had been 
done without finding ore in commercial quantity. 

^Abstracted from Hamilton’s unpublished report to Tennessee Geol. Survey. 

^Abstracted from Hamilton’s unpublished report to the Tennessee Geol. Survey. 
















130 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Chestnut Ridge prospects 

Chestnut Ridge forms the divide between Doe River and George 
Creek. On the west side of the ridge about half way down the slope 
of Little Rock Ivnob is a cut and small tunnel in a vein of epidotized 
pegmatite containing a one foot wide magnetic seam. The country 
rock is a schistose granite. It is mapped by Keith as Cranberry granite. 

From an eastern spur of Chestnut Ridge, locally known as Straw¬ 
berry Ridge, some ore was shipped in 1890. 

About a mile west of Little Rock Knob are outcrops and magnetic 
attractions over an east-west belt about 4,000 feet long. The country 
rock is Cranberry granite and the vein matter like that at Cranberry. 
A few pits and small piles of ore can still be seen, but other visible evi¬ 
dence of the vein is lacking. The work at this place was done between 
1885 and 1890 under the direction of J. R. Engelbert, according to 
Hamilton* 3 . It apparently uncovered a fairly large ore body. 

These openings are probably the ones mapped by Keith 84 in Carter 
County near the State line, and referred to in the text as prospects. 

Magnetic City prospects 

At about the location of the Engelbert openings the vein turns 
sharply to the south, crosses into North Carolina and continues south¬ 
ward until lost. 

About 1 mile south of the State line is a group of prospects which 
are probably those described by Nitze 85 under the name “Jenkins ore 
bank,” and mentioned in the Tenth Census report as being on the 
Wilder place. The main openings are situated miles above the 
mouth of Greasy Creek and 1 mile south of the Tennessee State line. 
One opening was a large open cut 100 feet long along the strike of the vein. 
It was 130 feet above the creek level, and was once worked to supply 
a forge at Magnetic City. The ore-body is reported to be 18 feet thick 
and to be like the ore-body at the Cranberry mine. The gangue is simi¬ 
lar to that at Cranberry, but the relation of the ore to the gangue is 
not known. The strike of the country rock which is “pegmatite and 
hornblende gneiss,” is N. 55° E., and its dip 45° SE. An analysis 86 of the 
dried ore taken from a small pile at the pit is given below. 

A smaller opening 350 feet above the creek level 87 is in a very 
lustrous compact ore free from gangue, about 5j^ feet wide, and near 
the summit of the ridge at about the same elevation is another opening 
which shows an ore body 1 foot thick at the top and widening to 5J4 

83 From S. H. Hamilton’s unpublished report to the Tennessee Geol. Survey. 

84 Keith, Arthur, U. S. Geol. Survey Geol. Atlas, Roan Mountain folio (No. 151'), Eco¬ 
nomic Geology map, 1907. 

85 Op. cit., p. 180. 

86 10th Census U. S., vol. 15, p. 560, 1886. 

87 Nitze, H. B. C., op.cit., p. 181. 



MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


131 


feet at the bottom of the cut. This also is free from gangue but in its 
upper portion it contains numerous quartz grains. The ore in these 
smaller openings differs from that in the larger one in that no horn- 
blende-epidote gangue is present. It also differs in that it is markedly 
titaniferous. The analysis below is of an average sample from the two 
openings: 


Partial analyses of ore from near Magnetic City, Mitchell County, N. C. 


Silica (Si0 2 ). 

Iron (Fe). 

Sulphur (S). 

Phosphorus (P). 

Titanium dioxide (TiCL) 
Phosphorus ratio (P-Fe) 


Lowvr cut 

63.41 

.012 

.019 


Average 
of upper cuts 

6.58 

54.48 

.023 

.033 

4.96 

.060 


Evidently the three deposits are not on the same vein, though close 
together. The occurrence at the large open cut is similar to that at 
Cranberry, both in the character of the ore and the nature of the gangue. 
The other occurrences are unlike that at Cranberry in both these features 
and are like the occurrences of titaniferous ore in Ashe county. On the 
other hand they are not on the titaniferous belt described by Nitze as 
being south of the Cranberry belt and parallel to it. It is probable 
that the deposits are entirely independent of the deposits on Nitze’s 
“Roan Mountain titaniferous belt,” and it is probable that they are 
independent of each other. At any rate, no connection can be shown 
to exist between them. 


Deposits between Magnetic City and Toe River 

From the Jenkins place Nitze 88 reports that the Cranberry belt 
of ore has been traced in a course approximating S. 50° to 55° W. to 
Toe River, but he mentions the occurrence of the vein only at the fol¬ 
lowing points: an outcropping on Bad Creek, miles above its mouth 
on the land of Chas. Garland; an opening on a body of “mixed ore and 
hornblende,” 1 mile northeast from the Garland place on the waters of 
Bean Creek; an outcrop near Peterson's mill on Brummetts' Creek, 2 
miles above its mouth, and another at the Elisha Street place on the 
northeast side of Toe River, half a mile below the mouth of Pigeon 
Roost Creek. Only the Peterson occurrence is described and the de¬ 
scription of this is limited to the statement that “the outcrop is fully 
30 feet across, in a massive bluff, but it is very lean; its strike is N. 
55 E.; dip SE.” 

The Peterson place was visited by the writer. It is now owned 
by Julie Herrell. The vein has been opened recently, as the dump is 
fresh. The opening is a hole blasted in the face of a cliff. The sur- 


* 8 Op. cit., p. 181. 










132 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


rounding rock is evidently Cranberry granite. This is crossed by 
narrow hornblende-epidote veins spotted by magnetite and cut by 
magnetite veinlets. The ore is a mixture of granular hornblende and 
small grains of magnetite. The occurrence is a small scale replica of 
the Cranberry vein, except that its walls are not so well defined. 

On the road between Relief and Red Hill two other small deposits 
have been uncovered. If these deposits are on the extension of the Cran¬ 
berry vein, it must have divided into a number of parts. There is evi¬ 
dently no continuous vein in this portion of the district, but the deposits 
are in short parallel independent veins. On the south side of the road 
about a quarter of a mile east of Brummet Post Office, J. W. Hughes 
opened a vein 2^ feet wide in a white gneiss, and a quarter of a mile 
east of the crossing of Rock Creek, A. G. Renfroe has some explorations, 
but in neither case was anything promising developed. 

Between Renfroe’s explorations and Rock Creek, blasting for road 
improvement has thrown out excellent, fresh rock that appears to be 
Cranberry granite. It is an evenly banded light-gray and dark-gray gneiss, 
in which the dark layers are much more micaceous than the light ones. 
Both contain many small red garnets. On Keith’s map of the Roan 
Mountain quadrangle this area is colored for Roan gneiss, but since the 
Roan gneiss is indicated as alternating with belts of Cranberry granite, 
it is possible that the rock being blasted is in a narrow belt that Keith 
did not see. 

MADISON COUNTY, N. C. 

Big Ivy mine 

After crossing Toe River no further outcrops of the Cranberry vein 
have been discovered, but the Big Ivy mine, which is in Madison County 
25 miles S. 50° E. from the mouth of Pigeon Roost Creek, is on its strike. 
The Big Ivy mine was not seen by the writer. Nitze, however, examined 
it and from his description we learn that it is on the only considerable 
deposit discovered in Madison County. 89 The mine, known also as the 
Heck mine, is 6 miles north of Alexander, on the south side of Big Ivy 
Creek, 3 miles above its mouth. Two principal openings and a number of 
minor ones on the north slope of a hill expose ore. The lower main 
opening, a long trench 150 feet above the level of Big Ivy Creek, cuts a 
vein 98 feet wide between walls of hornblendic gneiss. About 46 feet 
of the vein is occupied by masses, or horses, of hornblende, epidote, and 
quartz (probably pegmatite). The other 52 feet consists of a hard 
compact magnetite, with the composition given below. The upper main 
opening is a long cut several hundred feet S. 40° W. from the trench 
and 30 feet above it. Here the ore-body was not entirely cut through. 
It was, however, uncovered for a width of 30 feet. This ore is more 


»90p. cit., p. 188-1S9. 




MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


133 


granular than that to the northeast and resembles the Cranberry “rat- 
tlesnake ore.“ Float has been found as far as 3 miles farther northeast, 
suggesting that the vein runs in this direction. 

In the Tenth Census Report 90 the ore is described as being a mix¬ 
ture in various proportions of pyroxene and magnetite, the former de¬ 
creasing toward the center of the vein, but being present to some extent 
throughout the entire deposit. It was estimated that the ore rich 
enough to bear transportation did not have a greater thickness than 
10 feet. Analyses of this ore are quoted below: 

Partial analyses of ore from Big Ivy mine, Madison County, N. C. 



Ore from 



trench 

Rich ore 

Silica (Si0 2 ). 

15.54 


Iron (Fe). 

48.54 

57.84 

Sulphur (S). 

.012 


Phosphorus (P) . 

.019 

.021 

Phosphorus ratio (P:Fe). 

.039 

.036 


90 10th Census U. S., vol. 15, p. 377, 1886. 








CHAPTER VII. 


MINES AND PROSPECTS IN SILICEOUS 

MAGNETITES 


ALLEGHANY AND ASHE COUNTIES, N. C. 
GENERAL STATEMENTS 


The siliceous magnetites of Ashe county were used as early as 1802 
in Catalan forges and the iron produced was shipped 91 as far as Charles¬ 
ton, S. C., where it enjoyed an enviable reputation. The ores were 
used locally as late as 1887, until improved transportation facilities 
allowed cheaper iron to enter the county, and drive out the better and 
more costly metal. During the war between the States the iron was 
used in the manufacture of gun barrels. Since 1887 the mines have for 



Figure 13. Map of portion of Ashe County, North Carolina, showing locations of 
magnetic iron ore deposits. (After H. B. C. Nitze.) 


the most part lain idle because of the difficulty of transportation, but 
the building of the A irginia-Carolina Railroad in 1914 opened up a 
portion of the county and during the past few years a little ore has been 
shipped from deposits near Lansing. In 1922 no mines were operating. 


9I Pratt, J. H., North Carolina Geol. and Econ. Survey Econ. Paper 34, p. 64, 1914. 












































MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


135 


The siliceous magnetites of the county have been described as 
occurring in two belts (Figure 13), that have been called the Ballou or 
New River belt and the Red Hill or Poison Branch belt. A third belt, 
which is designated the titaniferous belt, contains a series of pits in 
titaniferous ores. The New River belt extends along the North Fork 
of New River, crossing it several times, and the Poison Branch is par¬ 
allel to the New River belt, but 2 miles farther west. Neither belt 
consists of a continuous series of deposits, but each comprises a num¬ 
ber of independent deposits on a series of nearly parallel veins lying 
close together. Some of the veins are short, being limited to the length 
of a single deposit, while others continue for comparatively long distances 
and comprises several deposits. The longest vein, perhaps, and that 
containing the greatest number of distinct deposits is that on the east 
side of New River about 1}/% miles west of Crumpler. The deposits 
themselves are thin lenses that lie in the courses of the veins, which in 
turn are parallel to the structure of the shists in which they lie. 

The ore has been stated to occur in thin lenses, but as a matter of 
fact, the commercial portions of the ore bodies are often in the form 
of veins or dikes of rich magnetite that cut masses of leaner ore. The 
lean ore comprises the lenses. Where these are enriched by the magne¬ 
tite veins they have furnished the commercial product. Pratt states, 

“the deposits are undoubtedly lenticular . . .and are pinching and widening 
in all dimensions. These lenses may continue for long distances along the 
strike and on the dip; then again, there may be a series of smaller lenses 
separated from each other by country rock or connected with each other 
by a thin seam of ore. Sometimes they may be so small as to be of no com¬ 
mercial value; while at other times they attain enormous size, both in length 
and depth. Usually these ore deposits are conformable to the enclosing 
country rock. Each ore locality has to be investigated as a separate unit, 
inasmuch as there is great variation in them ...” 

The ores of all the deposits are granular mixtures of pyroxene, 
hornblende and magnetite or of magnetite, hornblende, epidote, and 
quartz. Most of the pyroxene and magnetite grains are cracked or 
shattered and the quartz is largely granulated. The epidote, where it 
occurs, is an alteration product of plagioclase. These rather low grade 
ores occur as veins from a few inches to 17 to 20 feet wide traversing 
gneisses or gneissoid granites parallel to their schistosity. In many 
places these veins are cut by veinlets of nearly pure magnetite, thus 
enhancing their content of iron. 

The old mines are difficult to study, since they have been long 
abandoned and originally they were never thoroughly developed. There 
is now little visible at their openings. Some information concerning 
them has been furnished by the geologists of the Tenth Census and by 
Mr. Nitze 92 , but very little of it is of geological value. Kerr and Hanna 93 

92 0p. cit., p. 65. 

93 Kerr, W. C., and Hanna, Geo. B., Ores of North Carolina: Chapter 2, Geology of 
North Carolina, vol. 2, pp. 180-181, 1888. 



136 MAGNETIC IRON ORES'OF EAST TENN. AND WESTERN N. C. 

refer to the existence of the deposits but give no details, except to note 
that the gangues of some of them are “largely pyroxene and epidote. 
The Tenth Census geologists 91 devote their discussion mainly to the 
composition of several of the ores. Nitze 95 described the openings and 
the widths of the veins and gives the results of the analyses of many of 
the ores. In a few cases he also names the rocks associated with the 
deposits and the minerals accompanying the ores, but rarely mentions 
any other geological details. 

KIRBY OPENING 

The Kirby opening is about half a mile north of Sturgill on a slope 
overlooking a small branch emptying into Helton Creek. It is on neither 
of the two belts of deposits recognized by Nitze, but is in an isolated 
deposit about 5 miles west of the Poison Branch belt, and is near the 
south end of Nitze’s “Titaniferous belt/' (page 135.) 

The ore-body at the Kirby place is exposed by two cuts made by 
the Pennsylvania Steel Co. in 1902, at heights of 55 feet and 90 feet 
above the branch on the west side. On the east side of the branch a 
long open cut was made by Mr. Sturgill in 1892. The ore is a vein 1? 
feet wide in a gangue of epidote and hornblende. Its analyses are re¬ 
ported by Pratt 96 (1) and by Nitze 97 (2) as follows: 


Partial analyses of ore from Kirby mine, Ashe County, N. C. 



1 

2 

Silica (SiCb). 

21.7C 

17.25 

Iron (Fe). 

43.10 

48.87 

Phosphorus (P) . 

. 057 

.066 

Sulphur (S). 

. 036 

.057 

Titanium dioxide (Tith). 

Tr. 

.210 

Chromium sesquioxide (C^Os) . . . . 


.000 


Nitze reports the dip of the accompanying schists to be 47° S-SE. 

At the time of the writer’s visit to the occurrence the openings had 
fallen in and consequently the relations of the ore to the surrounding 
rocks were not visible. An exposure at the highest opening is of a dense 
rock composed of a banded aggregate of epidote and hornblende. Frag¬ 
ments of the ore picked from the dump consist of granular hornblende 
and magnetite with streaks of epidote here and there. From this very 
scanty evidence it is inferred that the ore is similar to that at Cranberry. 

In thin section the ore resembles very closely that of the Peg Leg 
mine (see page 127 and Plate II, B ), which is believed to be on the 
Cranberry vein. It is made up almost exclusively of pyroxene and 
magnetite (Plate XX, A). The pyroxene is a light-green variety that is 

94 Willis, Bailey, Notes on samples of iron ore collected in North Carolina: 10th Census 
U. S., vol. 15, pp. 324-5, 1886. 

95 Nitze, H. B. C., Iron ores of North Carolina: North Carolina Geol. Survey, Bull. 1, 
Raleigh, 1893. 

"Pratt, J. H., Op. cit., p. 71. 

97 Nitze, H. B. C., Op. cit., p. 160. 









PLATE XX. 




(A) Photomicrograph of magnetite ore from Kirby exploration, Sturgill, 
Ashe Co., N. C. Section shows only magnetite and uralitized pyroxene. The light 
area is a hole. Ordinary light. X60. 

(B) Photomicrograph of hornblende granite ‘horse’ in Cranberry vein, show¬ 
ing epidotization of plagioclase. The dark gray is hornblende, the light gray small 
crystals of epidote, and the white an aggregate of granular quartz and fresh feldspar. 
Ordinary light. X50. 




138 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

slightly pleochroic, probably because partially changed to hornblende. 
It contains as inclusions series of very fine needles and plates, like the 
rutile needles often observed in the augitic component of basic igneous 
rocks; and often larger yellow grains of the same mineral surrounded by 
pleochroic halos. In places it is stained by limonite and by green 
patches of ill-defined hornblende, which is in large equidimensional an- 
hedrons with smooth outlines. The magnetite is in small crystals em¬ 
bedded in the pyroxene and in large irregular and ragged-edged pieces 
lying between the pyroxene grains. Both magnetite and pyroxene are 
cracked and in the cracks are veins of small grains of epidote and mag¬ 
netite, and a little uralite. 

The section is very different from sections of the titaniferous ores 
but is almost identical in character with sections of the Peg Leg ore 
(Plate II, B), which in turn are similar in many respects to sections of 
Cranberry ore. The Cranberry ore is believed to be related in origin 
to the pegmatites that are so abundantly represented in the vein-filling 
at Cranberry, and by inference, therefore, the Kirby ore is thought to 
be intimately connected with pegmatite, although no definite pegmatite 
is visible in the vicinity of the mine. This is not surprising, however, 
since only a few square feet of the pit walls can be seen. 

There is no country rock exposed near the mine holes, but on Helton 
Creek, three-quarters of a mile south, is a series of light-gray schists in 
layers from 8 feet to 18 feet thick, striking about N. 80° W. and dipping 
25° S. The heaviest layers are of a rather fine-grained rock composed 
mainly of a granular mixture of actinolite, or tremolite and a light 
colored chlorite with a little calcite and feldspar and an occasional flake 
of dark mica. A few very tiny veinlets of quartz are visible, but other¬ 
wise the rock looks rather basic. The layers are only slightly schistose 
except on their borders where they appear to have been sheared, giving 
rise to hornblende partings. The coarser grained layers have the same 
composition as the fine-grained layers just referred to, but, in the field 
they look very much like squeezed conglomerates. 

Thin sections of the finer-grained rocks show fragments of a very 
much decomposed plagioelase in a mass of zoisite, epidote, emphibole, 
and chlorite. Most of the amphibole, which is fibrous and very light- 
green, replaces anhedrons of some mineral, but much of it is scattered 
irregularly through the section in small fibers. The zoisite and epidote 
are associated with little plates and fibers of chlorite and remnants of 
plagioelase, forming areas that were probably once occupied by plagio¬ 
elase. Between the amphibole and the feldspar areas are seams of fibrous 
amphibole and chlorite and grains of epidote in a matrix of crushed 
feldspar and in this are embedded masses of leucoxene and small pieces 
of titaniferous magnetite surrounded by broad rims of luecoxene. The 
only evidences of original texture, or fabric, discernible suggest coarse 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


139 


diabases. It is possible, however, that the rocks are phases of Keith's 
metarhyolites that are known to occur quite abundantly nearby, in 
Carter County, Tenn. 

DEPOSITS IN THE POISON BRANCH BELT 
General description 

The Red Hill or Poison Branch belt of deposits as defined by 
Nitze 98 enters Ashe county at its northeast corner and runs southwest a 
distance of about 10 miles, where it is lost. The belt contains a number 
of parallel veins, some of which are short and others comparatively long 
and in these are ore-bodies, which are usually richer portions into which 
there have entered masses of magnetite or of mixtures of magnetite and 
hornblende. Throughout most of their extent the veins are too poor 
to work profitably, and others are too small, but in some places their 
enriched portions may be large enough to warrant mining. 


Pugh and Smith openings 

The northeasternmost openings on this belt were not visited. They 
are described by Nitze 99 as consisting of cuts about 400 yards apart. 
The northern ones, on the land of L. A. Pugh, are a trench and a pit on 
Ben’s Creek in Allegheny County a quarter of a mile from New River. 
In the trench 2 feet of ore were exposed but the pit was sunk only to the 
top of the ore. In both cases the ore was a friable, granular magnetite, 
associated with epidote-hornblende schists. 

About 400 yards southwest of these openings on the summit of a 
ridge owned by J. L. Pugh is a cut 105 feet long at an elevation of 240 
feet above the river. Its southeast end crosses a deposit of “mixed ore 
material” reported to be 40 feet thick and its northeast end cut about 
30 feet of a similar, though harder material. Between the two was a 
“decomposed feldspathic mass.” The ore is coarsely granular, friable 
and manganiferous. Its gangue is the usual mixture of epidote and 
hornblende. 


About 400 yards southwest of the last described opening is another, 
shallow one on the property of W. B. Smith. In it was seen a 2 foot 
wide deposit of micaceous ore which is currently reported to pass down¬ 
ward into 4 feet of hard ore. Its strike is N. 27° E. and its dip 57° SE. 
The micaceous ore appears to extend southwest on to the land of Noah 
Dancy, but only surface material was seen. 


Partial analyses of ore samples from openings in Allegheny County, N. C. 


Name of exploration Si02 Fe Mn S P P ratio 

L. A. Pugh. 22.74 45.44 .049 .022 .048 

J. L. Pugh. 21.11 43.17 4.62 .048 .006 .013 

W. B. Smith. 55.76 .040 .071 

Noah Dancy. 63.49 .17 6 .276 


98 Op. cit., p. 138. 
"Op. cit., p. 138-139. 









140 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Deposits on Helton Knob 

The next opening to the southwest is near the base of the north¬ 
east slope of Helton Knob on a southern branch of Grassy Creek in 
Ashe county. Old pits are still recognizable but they are nearly obliter¬ 
ated. There are two thin seams of soft, friable ore that was in great 
demand at the old forges. They are in a decomposed schistose gangue. 
At Pasley forge this soft, superficial material was washed before use. 
As the same preparation is possible for other ores of a similar character, 
where weathering of the hard material has penetrated deeply, Nitze’s 
figures showing the resulting benefieiation are quoted. 100 

Partial analyses of crude and washed ore from opening on Helton Knob, Ashe County , 

N. C. 



Crude ore 

Washed ore 

Silica (SiOi). 

_ 21.02 

11.08 

Iron (Fe). 

_ 48.10 

58.93 

Sulphur (S). 

_ .06 

.068 

Phosphorus (P) . 

_ .036 

.033 

Phosphorus ratio (P:Fe). 

. ... .074 

.056 


About a quarter of a mile south of west from these openings is an 
outcrop of hornblende gneiss containing small lenticules of hard magne¬ 
tite, one of which is 3 feet wide, and about 200 yards farther southwest 
on another ridge are large masses of float ore indicating a second vein. 

Blevins openings 

The veins can be traced across Helton Knob by openings and the 
dip needle to the land of Dave Blevins's heirs on the western foot-hills 
of the knob. Here were a number of openings which are now closed. 
One of these, an open cut 60 feet above the level of Roberts Branch, 
was 48 feet long exposing 3 streaks of compact magnetite 7^, 4j^ and 
2 feet thick in gangues of hornblende and epidote separated by gneiss. 
Ore fragments taken from the dumps show a fairly finely granular py¬ 
roxene and magnetite mixed with a little quartz. 

The thin section of this ore reveals a very simple composition very 
much like that of the Kirby (page 136) opening. It consists almost 
exclusively of green pyroxene, magnetite, and quartz. The pyroxene 
constitutes possibly over 75 per cent, of its mass. It is in polygonal 
grains with smooth outlines snugly fitted together, frequently with only 
a stain of limonite between. In some places the grains may be separated 
by a very thin seam of granular material containing small particles of 
magnetite and epidote. Here and there the grains are crossed by crush 
zones in which are small pieces of pyroxene, quartz, epidote, garnet, 
and magnetite. Most of the quartz is in the triangular spaces between 
neighboring pyroxenes. Many of its grains exhibit strain shadows. 


100 Nitze, H. B. C., Op. cit., pp. 139-142. 








MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


141 


The magnetite is in the corners between the pyroxenes, either alone 
or with quartz. A few pieces are apparently embedded in the pyroxene, 
and others are strewn at the contacts between neighboring grains. 

An analysis of a sample taken across the entire series of layers is 
given 101 in Column 1. 

Another opening 100 feet N. 79° E. and 100 feet higher is an open 
cut on the dump of which is ore with the composition shown in column 2. 
This may be the opening pointed out to the writer as having been made 
by Major Duld. Where the rocks associated with the ore are hornblende- 
epidote schists cut by veins of epidote and quartz. Other pits indicate 
that the “ore-bearing formation" is wide. 

Partial analyses of ores from the Blevins openings on Helton Knob, Ashe County, N. C. 



1 

2 

Silica (Si()o). 

.... 29.90 

31.67 

Iron (Fe). 

.... 36.35 

32.66 

Sulphur (S). 

.... .038 

.042 

Phosphorus (P) . 

.. . .022 

.103 

Phosphorus ratio (P:Fe). 

.... .060 

.315 


The rock associated with the ore at all the pits is a schist containing 
the usual hornblende and epidote. No country rock crops out in the 
neighborhood, but that exposed at the Falls of Helton Creek near Red 
Hill is a white gneiss that looks very much like Cranberry granite. 

Red Hill openings 

At Red Hill the whole top of the hill at the junction of Helton 
Creek and Roberts Branch is dug over by pits and trenches. No rock 
outcrops were seen but many fragments of ore were found in the dumps. 
Pratt 102 describes the occurrence as follows: 

“Red Hill rises about 170 feet above the level of the creek, and a trench over 200 
feet in length has been made from one side of the hill to the other near its summit. 

“While it did not expose a vein of solid magnetite ore, it did show a decomposed 
schistose rock, which carried almost throughout its entire extent masses and particles 
of magnetite scattered through it. 

Nitze 103 calls attention to the fact that another opening 30 yards 
west from the north end of the long trench exposed a solid seam of hard 
magnetite 5 feet thick in a mass of epidote and quartz. Analyses of 
an average sample of the loose ore from the long trench (1) and of a 
sample of the hard ore (2) show them to be practically alike in compo¬ 
sition : 

ioiNitze, H. B. C., Op. cit., p. 142. 

uuPratt, J. H., North Carolina Geol. and Econ. Survey. Econ. Paper 34, p. 70, 1914. 

i°30p. cit., pp. 143-145. 










H2 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Partial analyses of ore from openings on 

Red Hill, Ashe 

County, N . C. 


1 

2 

Silica (Si0 2 ). 

19.83 

32.00 

Iron (Fe). 

51.55 

37. 14 

Sulphur (S). 

. 137 

.071 

Phosphorus (P) . 

.042 

.004 

Titanium dioxide (TiCb). 

.207 

. 106 

Phosphorus ratio (P:Fe). 

.081 

.010 


At other openings ore of the same quality is uncovered, but some of 
the deposits are injured by the presence of pyrite and in one case, viz.: 
in an opening on the bank of Helton Creek and 60 feet above it, the 
magnetite is split by a lens of highly pyritiferous ore about 5 feet thick. 
An analysis of a sample taken across the ore body at this place gave: 
iron (Fe), 23.39 per cent; sulphur (S), 1.67 per cent, and phosphorus 
(P), 0.109 per cent. 

Commenting upon the economic value of the deposit Nitze 104 writes: 

“The soft ore is admirably adapted to magnetic concentration, although it is very 
doubtful if it exists in any quantity, being most likely the weathered and broken- 
down portions of the original beds or lenses, which latter must be and are found in 
depth, hard and unaltered . . . The lenses may widen with depth and contain much 
cleaner ore, or vice versa; at any rate the conditions must be carefully determined 
in order that a definite opinion may be arrived at. The ore is low in phosphorus, far 
below the Bessemer limit; as already mentioned, the great danger is that it may become 
detrimentally high in sulphur below the water level.” 

McClure’s Knob deposits 

The belt of deposits continues southwest across McClure’s Knob 
where exposures and a number of openings reveal a series of thin parallel 
veins distributed over a width of 2,000 feet. 105 The strike of the country 
rock, which consists of gneiss and hornblende schist is N. 50° to 53° E., 
and its dip is at various angles to the southeast. The openings are 
all shallow, revealing nothing but the presence of ore. Among the 
openings and exposures referred to by Nitze are the Tolley cut, just 
north of the main summit of the Knob, where 2j^ feet of fine granular 
ore mixed with hornblende are exposed; a tunnel 500 feet S. 25° W. 
from the cut, where a lens of magnetite of unknown size in hornblende 
and epidote was uncovered on the western slope of the knob; the Blevins 
forge opening, about 500 feet N. 15° E. from the Tolley pit, on the north 
side of the knob, where a vein 3 feet wide was found; an exposure 200 
feet south of the Blevins forge opening; and the Price opening 900 feet 
S. 20° E. from the “comb of the ridge" where a lens 3 feet thick is ex¬ 
posed lying on a micaceous schist foot wall. Many small pits and out¬ 
crops between those mentioned indicate that the vein is nearly continu¬ 
ous over the knob. In addition, on the west spur of the knob near the 


104 Opp. cit., p. 145. 

105 Nitze, H. B. C.. Op. cit., p. 146. 










MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


143 


road crossing it from northeast and southwest is another opening on the 
property of Mr. Niece. This is west of the Price place and consequently 
is probably on another vein. No definite information concerning the 
relations of the ore could be obtained from it. Analyses 10 * 5 of samples 
from these various deposits are: 

Partial analyses of ore from deposits on McClure's Knob, Ashe County, N. C. 

Tolley Tunnel Blevin’s Out- Price Price 

opening opening forge crop opening opening 


Silica (SiO,). 23.23 21.58 22.78 28.78 11.46 16.50 

Iron (Fe) . 44.87 47.07 43.03 42.38 51.30 45.87 

Sulphur (S) . .036 .05 .02 .03 .06 .025 

Phosphorus (P) . .053 .07 .14 .03 1.12 .904 

Phosphorus ratio (P:Fe) . .118 .148 .325 .070 2.183 1.970 


Nitze remarks on the high phosphorus content of the McClure’s 
Knob ores and suspects that this characteristic will condemn them for 
use in the near future, in view of the existence in the same general region 
of so many deposits of ores low in phosphorus. 

This series of deposits can be traced by float some distance south¬ 
west but it is finally lost on the south side of Old Field Creek, and an¬ 
other more easterly series begins at Poison Branch and runs southwest. 

Poison Branch mine 

The Poison Branch mine is at the head of Poison Branch, on the 
divide between Old Field Creek and Silas Creek. The mine is an old 
one. Ore was obtained from two open cuts on the northeast side of 
the road that passes its site. (Figure 14) Near the summit of the hill, 
50 feet below its top on its west slope, is a tunnel 181 feet long with cross¬ 
cuts at its end and 45 feet and 114 feet from the end. The two inner 
crosscuts exposed a vein about 5 feet wide striking N. 40° E. and dip¬ 
ping 45° SE. The third crosscut could not be examined by Pratt 107 
from whose report this description is taken. The foot-wall of the deposit 
is mica schist and the hanging-wall hornblende gneiss. 

Nitze 108 describes the same open cut as exposing magnetite in two 
places and illustrates sections of the ore vein. He states that the ore 
in the upper outcrop (see Figure 14) is soft and micaceous, and that in 
the lower one it is hard and its gangue is hornblendic. No account is 
given of the other two openings. It is said, however, that several hun¬ 
dred feet to the northwest are some small openings, with dumps contain¬ 
ing fragments of ore, thus indicating the presence of another ore vein. 
In the Tenth Census Report 109 , the ore at this place is described as con¬ 
sisting of two parts. “The upper is 1 foot thick and consists of mica 
schist, which incloses large crystals of magnetite; it is much decomposed 


u. s 


in# Nitze, H. B. C., Op. cit., pp. 145-148. 

‘ 0 ?Op. cit., p. 67. 

108 Op cit., pp. 148-150. 

io»willis Bailey, Notes on samples of iron ore collected in North Carolina: 
, vol. 15 , p. 325, 1886. 


10th Census 









144 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


and is quite soft. Immediately beneath it is a hard, fine hornblende 
schist 2 feet thick, which is also impregnated with magnetite.” 



Figure 14. Map of openings at Poison Branch mine, Ashe County, North Carolina. 
(After H. B. C. Nitze.) 


Samples of the upper and lower parts of the exposure show: 

Partial analyses of ore from Poison Branch vein, Ashe County, N. C. 

Upper part Lower part 

Iron (Fe). 62.78 50.63 

Sulphur (S) . 1.00 .076 

Phosphorus (P). .041 .016 

Phosphorus ratio (P:Fe) . .065 .032 


The only contribution the writer can make to the discussion is to 
state that at the lower opening, southwest of the road, there is a large 
dump of comparatively fresh material and that on it are fragments of peg¬ 
matite, pegmatite ore and rich granular ore. The pegmatite ore is a 
mixture of granular magnetite, quartz, and feldspar. 

In the schists that accompany the ore are streaks of epidotic gneiss 
like those at Cranberry. 

Nitze gives analyses o a sample taken from the opening “on the 
south side of the road,” presumably that on its southwest side, and of 








MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


145 


several samples taken from the cut at its upper and at its lower ends. 
These are reprinted below, and with them the analysis of an average 
sample quoted from Pratt’s 110 paper: 

Partial analyses of ore from Poison Branch mine, Ashe County, N. C. 

Opening south Cut, Cut, Average 

side of road upper end lower end ore 


Silica (SiOo) . 28.00 5.55 20.30 20.05 

Iron (Fe) . 37.30 01.44 45.00 45.25 

Sulphur (S) . .09 .00 .13 1.58 

Phosphorus (P) . .014 .003 .011 .052 

Titanium dioxide (Ti0 2 ) . .082 .040 Tr. 

Phosphorus ratio (P:Fe) . .038 .005 .024 .115 


Openings between Silas and Piney creeks 

Southwest of Poison Branch mine several openings aid in tracing 
one of the members of the belt as far as Piney Creek about 234 miles 
distant. About three-quarters of a mile S. 41° W. of the Poison Branch 
openings are shallow pits on the summit of a ridge on Munroe Barker’s 
land, where a little ore was uncovered in a hornblende schist. About a 
mile S. 70° W. from these are three other small openings on the land of 
Sam McClure, exposing several parallel veins in a hornblende gangue, 
and about 700 yards S. 45° W. from these, on the property of John Par¬ 
sons is a shallow pit near the road that shows 3 feet of soft ore, also in 
hornblende. 

None of these seems important. They are of interest mainly in 
locating the continuation of the mineralized belt southwesterly. They 
are certainly not all on the same vein, nor is it certain that any one of 
them is on the prolongation of the Poison Branch vein. Analyses of 
surface samples of the ores at the three localities are given by Nitze 111 , 
as follows: 


Partial analyses of ores between Poison Branch and Piney Creek, Ashe County, N. C. 



Barker place 

McClure place 

Parsons place 

Silica (SiOo). 

. 11 01 

38-71 

6-94 

Iron (Fe). 

. 53.9(1 

27.40 

58.50 

Sulphur (S). 

... .027 

.06 

.055 

Phosphorus (P) ......... 

...... .034 

.083 

.004 

Phosphorus ratio (P:Fe). . . 

. . 0G3 

.303 

.007 


The first notable deposit southwest of the Poison Branch mine is on 
a high ridge about half a mile northwest of the Parsons place, on land 
formerly owned by Douglas Blevins, where a seam of hard magnetite 
8 feet wide in an epidotized gneiss has a strike N. 55 ° E. and a dip 45 ° SE. 
The openings are now closed but on their dumps are a few fragments 
of ore and of banded epidote-quartz and epidote-hornblende schists. 


iioQp. cit., p. 71. Analyst: Crowell and Murray, Cleveland, Ohio. 
■ ■'Op. cit., pp. 151-152. 
















146 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

The ore is a fine, granular aggregate of magnetite in grains with crystal 
outlines. Pratt 112 writing of this deposit says: 

“The ore is exposed in a vein which outcrops in a ledge above Mr. Fall's house. . . 
About GO feet below the summit of the ridge a tunnel was run 60 feet into the hill, which 
cut but did not penetrate the vein.” 

Nitze’s analyses of samples of the ore show it to be comparatively 
high in phosphorus. His figures for two samples are: 

Partial analyses of ore from Douglas Blevins place, Ashe County, N. C. 



1 

2 

Silica (Si0 2 ). 

_ 23.90 

27.67 

Iron (Fe). 

_ 40.08 

40.62 

Sulphur (S). 

_ .09 

.095 

Phosphorus (P). 

_ .904 

.740 

Phosphorus ratio (P:Fe).. 

.... 2.222 

<34 

GO 


Ore has been found northeast of this point on the divide between 
Silas and Grapevine creeks, where there is a series of openings from 
which much gravel ore and a little hard ore have been taken. On the 
dumps are pieces of streaked ore, but nothing is known of its manner 
of occurrence. It is, however, like the other ore in the neighborhood. 

Piney Creek opening 

On Piney Creek near the junction of the Piney Creek and Lansing 
roads, about half a mile south of the Blevins openings, on the northeast 
side of the creek a few feet above the creek level an open cut was made 
on the land of U. Ballou. Pratt 113 states that this exposed a vein of ore 
12 feet wide. “The ore is very coarse grained, very free from gangue, 
but it contains near its center a 15 inch seam or vein of soft brownish 
black manganese-iron oxide.” Analyses of the samples of the compact 
magnetite and of the brownish-black ore are quoted below, in lines 1 
and 2. 

About 85 feet north of this cut on the slope of the hill another cut 
exposed a granular ore of the same appearance as that exposed in the 
creek cut. Its width was not determined. The analysis of this ore is given 
in line 3. About 40 feet farther up the slope the ore was again encountered 
in a pit. “The lateral distance represented by the exposures made in 
the three cuts mentioned above is approximately 350 feet. The lead 
has been traced by means of float for a considerable distance beyond 
that exposed in the upper cut. The above all indicates that there is a 
lens of very large size on this property.” 

If the width of 12 feet is maintained between the northernmost and 
southernmost openings, the deposit thus far exposed contains about. 
65,000 tons of ore above a depth of 100 feet below the creek level at the 


112 Op. cit., p. 67. 
u, Op. cit., pp. 68 and 71. 









MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


147 


most southerly pit. If the width of the vein is greater than 12 feet, 
as it is reported to be by Mr. Cooke, and its length is greater, as is in¬ 
dicated by the float northeast of the upper opening, the tonnage will 
naturally be correspondingly greater; but with the evidence now avail¬ 
able an estimate of a greater tonnage than 65,000 tons is not warranted. 

Nitze 114 furnishes several analyses of samples of the ore at the open¬ 
ing on the creek. Four of these are reprinted in lines 4, 5, 6 and 7: 



Partial analyses of ore from 

Ballou's Piney Creek openings, 

Ashe 

Coun 

ty, N. 

c. 



Si0 2 

Fe 

Mn 

S 

P 

Ti0 2 

P ratio 

l a . 

Opening on creek. 

2.0G 

64.56 

2.59 

Tr. 

.014 

.00 

.022 

2 6 . 

Soft, brownish-black ore . . 


42.80 

17.48 . 

• • • 

• • • • 

• • • • 

• • • • 

3 C . 

Ore from upper cut. 


65.50 

2.81 . 

• • • 

• • • . 

• • • • 

• • • • 

4. 

Hard ore. 

.614 

65.09 

3.98 . 

007 

.019 

.... 

.029 

5. 

Hard, coarse, granular ore. 

3.12 

62.10 

3.66 . 

085 

.017 

• • • • 

.027 

6. 

Soft, earthy ore. 

... 10.64 

39.35 

9.63 . 

• • . 

.022 

• • • • 

.056 

7. 

Hard ore. 

3.20 

65.40 

2.58 . 


.011 

.00 

.016 


a. Analyst: Frank Drane, Charlotte, N. C. 

b. Analyst: Crowell and Murray, Cleveland, Ohio. 

c. Analyst: Crowell and Murray, Cleveland, Ohio. 


At the time of the writer’s visit the cut at the creek was caved, but 
on its dump were numerous fragments of pegmatite and of a coarse 
granular magnetite that is admixed with a very little white earthy ma¬ 
terial that may be a decomposed feldspar. 

There are no exposures of the country rocks near the Ballou openings, 
but at the junction of the first cross-road south of the openings there are 
abundant exposures of a pink augen-granite-gneiss. 

Francis and Henninger openings 

Farther to the southwest openings are again found on the Francis 
and the Henninger properties, but at neither of these localities are there 
large deposits indicated. 

The Francis deposit is about a third of a mile west of the Piney 
Creek exploration, on the road from the latter point to Lansing. Nitze 115 
refers to an opening 250 feet above the level of the creek on the land of 
Robt. Francis. He says, 

“a slope, 20 feet deep, exposes 10 feet of soft manganiferous ore on the outcrop, pinch¬ 
ing out to considerably less than this at the face of the same. 

“Throughout this soft material are scattered grains of hard magnetite. There 
is evidently a roll or fold in the bed at this point, the dip being . . . 20° N. of E., and 
strike N. 34° W. . . . The ore carries an excessive amount of hygroscopic moisture. 

“Float ore is found scattered over the hill to the northeast . . . and immediately 
on the roadside a tunnel was driven some 75 feet long, but it has caved in.” 

Nothing new was learned by a visit to the locality in 1919, though 
a new tunnel had been dug in the rear of the Francis house after Mr. 
Nitze’s visit; but this, too, is caved. 











148 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Analyses of samples of ore from the slope and one of loose ore found 
at the mouth of the tunnel are quoted from Nitze's report: 

Partial analyses of ore from Franeis property, Ashe County, N. C. 


Silica (Si0 2 ). 

Natural ore 
from slope 

3.49 

Dry ore 
from slope 

10.82 

Dry ore 
from slope 

1.73 

Iron (Fe). 

27.23 

47.43 

64.51 

Manganese (Mn). 

5.22 

8.96 

3.19 

Sulphur (S). 


.... 

.040 

Phosphorus (P) . 

.058 

.085 

.120 

Phosphorus ratio (P:Fe). . . 

.213 

.180 

. 186 

Water (H 2 0). 

42.GO 

.... 

.... 


West of the openings on the Francis land are two small open cuts 
on the Henninger property. They are 600 feet apart, and both uncovered 
granular ore, but nothing very definite is known about it. 

Openings on Turkey Knob 

The Stewart land referred to by Nitze 116 is on the west side of the 
summit of Turkey Knob, about half a mile west of the Francis land. 
When this place was visited two trenches were found, but evidently 
they are not the openings that were described by Nitze, as they show 
evidence o' much later working. In neither trench was any ore seen in 
place, but on their dumps were fragments of lean ore, some of which 
consisted of a hornblende gneiss with scattered grains of magnetite 
and others of parallel layers of brown quartz, hornblende schist and a 
dark schist containing magnetite. 

The brown layers contain subordinate white sugary quartz seams, 
and the magnetite layers much hornblende. The brown layers are com¬ 
posed mainly of interlocking quartz grains, with here and there embedded 
in the aggregate large and small pink garnets, an occasional flake of bio- 
tite and more frequent, but not common, wisps of uralite. The garnets 
are arranged in lines and the biotite and uralite are elongate in the same 
direction. The quartz, however, is in equidimensial grains and there is 
no evidence of a definite parallelism among them. 

The darker layers differ from the lighter ones only in the greater 
amount of uralite they contain and in the presence in them of a little 
magnetite and epidote. The magnetite is in elongate grains and small 
masses and the epidote in small crystals and grains intermingled with 
the amphibole. The quartz grains are slightly elongate in a common 
direction, which is the same as that of the elongation of the magnetite 
and amphibole. In none of the grains are there any strain shadows 
visible. 

The specimen studied is not an ore. It is a schist that has been 
strongly silicified. 


u6 Op. cit., p. 154. 











MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


149 


Xitze states in his description of the locality that the ore found at 
two openings, 100 feet apart in elevation, is a hard, compact crystalline 
magnetite in a 5 foot vein having “a gangne of epidote, gneiss and 
quartz.” 

He gives analyses of two samples: 

Partial analyses of samples of ore from the top of Turkey Knob, Ashe County, N. C. 


Silica (SiOo). 

Lower 

opening 

_ 15.22 

Upper 

opening 

26.56 

Iron (Fe). 


47.14 

Sulphur (S). 

_ .015 

.06 

Phosphorus (P) . 

.... .015 

.023 

Phosphorus ratio (P:Fe). 

_ .025 

.048 


In a third analysis of the same ore a trace of Ti0 2 was found. 

Graybeal property 

About half a mile S. 30° W. of the Francis property is the center 
of a considerable exploration on the lands of the Graybeal heirs. (Fi¬ 
gure 15.) The deposits here were worked a long while ago to furnish 
local forges with ore. Nitze 117 describes two openings on the property— 
one a narrow open cut 50 feet long, “showing a bed of soft shot ore in 
decomposed hornblende,” with a one-foot thick seam of manganiferous 
earth in its “front part.” He does not state just where this cut was 
but it was probably on the southwest slope of the hill on the summit 
of which is the larger main opening. This main opening was a cut 50 
feet long near the summit of the ridge. It exposed two seams of ore 
4 feet and 18 feet thick. The 4-foot seam was a compact magnetite free 
from gangue, while the upper, 18-foot seam contained some hornblende. 
Analyses of samples from these seams are given as follows: 


Main opening 


Silica (Si() 2 ). 

First 

opening 

28.95 

Lower 

seam 

6.85 

Upper 

seam 

11.57 

Iron (Fe). 

42.60 

63.55 

55.24 

Manganese (Mn). 

1.58 

.... 

.... 

Sulphur (S). 

.04 

Tr. 

.075 

Phosphorus (P) . 

.008 

.009 

.005 

Titanium dioxide (Ti0 2 ). . . . 

. .... 

.06 

.... 

Phosphorus ratio (P:Fe). . . . 

.019 

.014 

.009 


After Nitze’s visit much more work was done on the Graybeal and 
adjoining farms. Pratt 118 describes this work and the new openings 
substantially as follows: 

“About one-half a mile northeast of the Waughbank (see page 183) property 
begins what is known as the Graybeal properties. The first property encountered is 
the Calvin Graybeal. Only a very little development work has been done on this 
property, but float ore has been encountered, which would indicate the continuation 
of the ore formation across the property. 















150 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


O Pit 



Contour in/erva/ 20 ft. 
/ Co tunne/ 


Figure 15. Map of Ashe County in the neighborhood of Lansing showing positions 
of the Graybeal property and the Ashe Mining Company’s mine. 


“A short distance north from the top of the hill on the Calvin Graybeal property 
on lands owned by the Patton family and Calvin Graybeal, a cut exposed magnetic 
iron ore mixed somewhat with the country schist. This may be part of an ore deposit 
that is known in that section as the “North vein,” which extends approximately pa¬ 
rallel with the regular ore formation, being approximately 200 to 300 yards north of 
the larger vein. 

“It is about one-fourth mile from the top of the Calvin Graybeal hill to the Joseph 
Graybeal property in a general northeast direction. The vein has a strike across 
this property of an approximately northeast direction, and it is dipping toward the 
southeast. The ore deposit has been prospected and developed by means of open cuts, 
pits, and tunnels for a lateral distance of at least 800 feet and a vertical distance of 
over 100 feet. A drill hole was made by the Pulaski Iron Company at a point about 
700 feet to the southeast of the first open cut, and 75 feet below. It is reported to have 
encountered the ore at a depth of about 200 feet. The dip of the vein would bring the 


117 Op. cit., pp. 155-156. 
118 Op. cit., pp. 68-70. 





























MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


151 


ore body to this point. The width of the ore body as encountered varied from 4 to 
15 feet. 

Ihe first cut examined was partially filled, so that the extent of the vein could 
not be determined. Good ore is exposed in the cut, thus showing the continuance of 
the ore body. This work was done by the Virginia Iron, Coal and Coke Company 
in 1907. Three hundred feet to the northeast another cut exposed the vein, which 
had a width of at least 15 feet of nearly solid ore, there being a little of the ore mixed 
with finely divided gangue rock. An analysis of this ore showed 63.50 per cent, metallic 
iron. At the mouth of the cut, about 30 feet from the vein, another small seam of ore 
V2 to 15 inches thick was exposed. Most of this work was done about 1890 or 1892. 
Part of it was done in the early days of iron mining in the county, when the ore was 
obtained for the Catalan forges. 

“Still further to the northeast a long open cut or trench was made by Mr. Sturgill 
in 1903 across the ore deposit. At the time of my visit, however, it was nearly all filled 
up, and the ore was only exposed at the east end of the cut. 

“Float ore has been found between all the cuts referred to. 

“On the opposite side of the hill several cuts and tunnels have been run which 
penetrated the ore body, showing that the ore was continuous through this hill. Most 
of the work was done by the Virginia lion, Coal and Coke Company in 1907. The 

first cut is about 300 yards northeast of the Sturgill cut referred to above. . . . Near 

the mouth of the cut an iron manganese seam of ore was encountered 6 feet wide, the 
distance between the two veins being 30 feet. 

“Thirty feet below this cut a tunnel was run into the hill. . . . Judging from 
the material found on the dump, the ore encountered in the tunnel was very similar 
to that in the cut referred to above. 

“Two hundred and fifty feet northeast of this tunnel another open cut was made 
by Dr. Tom Jones in 1905, and work was continued by the Virginia Iron, Coal and 
Coke Company in 1907. This cut exposed a seam of magnetite about 4 feet wide, 
which it penetrated. In the upper end of the cut there was exposed a mixture of pyrite 
and hornblende. Thirty feet below and 30 feet northeast of this cut a tunnel was run 
by the Virginia Iron, Coal and Coke Company, and later continued by Dr. Jones. 
This penetrated the ore body. There was exposed near the mouth of the tunnel a 
manganese iron seam of ore. 

“From this point it is 300 yards northeast to the Joseph Graybeal line. Beyond 
this property is the Dr. Thomas Jones land which has been prospected ... by means 
of shallow cuts and pits." 

Analyses of ore from 3 of the openings were made by Crowell and 
VI urray. The results quoted by Pratt, are given in the following table: 

Partial analyses of ore from the Jos. Graybeal 'property, near Lansing, Ashe County, N. C. 


Silica (SiCC) . 

First 

cut 

1. 15 

Second 

cut 

Large cut, 
top of hill 

Iron (Fe). 

67.40 

63.50 

63.15 

Manganese (Mn). 

. .... 

.... 

3.58 

Sulphur (S). 

.06 

.... 

.... 

Phosphorus (P) . 

.005 

.... 

.... 

Titanium dioxide (TiCL). . . . 

.00 

.... 

.... 


On the writer’s visit to the Graybeal property in 1919 a number of 
openings were seen in a northeast line, but it was difficult to identify 









152 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

any of them with those described by Nitze or Pratt. Some of the open- 
ings are comparatively recent. Mr. Cooke, who made some of tlie 
newer openings and enlarged some of the older ones, declares that lie 
shipped from them about 1,000 tons of ore. He followed a rich vein 
varying in width from 18 inches to 12 feet, that cut through a larger 
vein of lean ore composed of magnetite, hornblende, and epidote. The 
rich ore runs irregularly through the vein-matter but on the whole it 
follows the strike of the larger vein, which is about northeast. In some 
places small quartz and pegmatite veins also traverse the lean ore. At 
some of the other openings there were noticed also veinlets of pure mag¬ 
netite cutting vein-matter irregularly, but they never cross the borders 
of the vein proper which usually trends in a straight line. 

Analyses 119 of carload lots of the Graybeal ore aggregating 911 tons 
showed limits of 44.00—61.08 per cent for iron and 0.0088—0.0262 per 
cent for phosphorus. All the cars but two showed more than 50 per cent 
of iron and their average was 54.30 per cent. 

The analysis 120 of a carload of the ore mined by Mr. Cooke in June, 
1916, showed: 


Partial analyses of Graybeal ore, Lansing, Ashe County, N . C. 


Silica (Si0 2 ). 

. 12.16 

Lime (CaO). 

.3.35 

Iron (Fe). 

. 61.80 

Magnesia (MgO). 

_ 2.00 

Manganese (Mn). 

. 1.82 

Titanium (Ti). 

.012 

Copper (Cu). 

.00 

Phosphorus (P). 

.0094 

Alumina (Al 2 0 3 ) . 

. 3.69 




A few years ago a tunnel was started near the bottom of the south 
slope of the hill a few yards north of the road between Lansing and Piney 
Creek in order to reach the lower portions of the deposits that outcrop 
on the crest of the hill 180 feet higher, but work was stopped before the 
ore was reached and there is thus no evidence to indicate whether the 
deposits continue to so great a depth or not. 

All the deposits in this area are certainly not on the same vein. 
Some of the veins may bend slightly and deposits not on the same straight 
line may indeed be the richer parts of a continuous vein. But the 
positions of the deposits with respect to each other are such that many 
of them cannot be explained on this supposition. It is much more 
probable that they are on different, but parallel veins. Mr. Cooke, who 
has explored the country around Lansing pretty thoroughly, insists that 
there are 5 distinct veins between the Ashe Mining Co.’s mine (see 
Figure 15) and Dr. Jones’s house which is about half a mile northeast 
of Lansing station. 

It would seem unwise to attempt to work any of the deposits on 
the Graybeal property without providing some means for concentrating 


119 Furnished by Mr. Geo. W. Cooke 
uoFurnished by the Cranberry Furnace Co. 












MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


153 


the ore, since in most cases it would be necessary to remove a slice of 
material 15 or 20 feet wide to gain room for mining. This would mean 
that work could not be limited to the rich narrow veins that intersect 
the lower grade ore that comprises the greater parts of the larger veins. 
Some veins might be worked profitably for a short time, but only by 
following their richest parts until a depth is reached beyond which the 
cost of raising the crude ore would be prohibitive. This depth would 
not be great with veins only 4 feet or 5 feet wide. Moreover, all but 
the richest ore would be left and therefore wasted, since it would not of 
itself bear the cost of mining. On the assumption of a minable width 
of 1? feet of material containing 75 per cent, of magnetite, and a length 
of 800 feet, the available marketable ore above the mouth of the tunnel 
on the south side of the hill after concentration would amount to about 
150,000 tons. 


Waughbank property 

About half a mile southwest of the Graybeal openings is the Waugh¬ 
bank property which consists of an open cut and a tunnel on the hill 
on the north bank of Horse Creek near where it crosses the Virginia 
and Carolina Railroad, 1}^ miles southeast of Lansing station. Ref¬ 
erence will again be made to the deposit at this place in the discussion 
of the Ashe Mining Co.’s mine. (See page 183.) 

Hampton Knob openings 

About three-quarters of a mile w 7 est of the Graybeal mine and about 
the same distance northwest of the Waughbank opening a vein crosses 
the north end of the crest of Hampton Knob v T here it has been opened 
by a shallow pit. Other pits and shallow trenches have been made on 
the northeast slope of the knob, but they have uncovered only small 
veins. These openings are sufficiently numerous to indicate the presence 
of ore veins, but are not so distributed as to indicate whether they are on the 
same vein or not. It is probable that no one of the veins is continuous 
w r ith any of those opened on the Graybeal land. Nitze 121 declares that 
the Hampton Knob ore lacks the manganiferous character of the Gray¬ 
beal ore and most probably therefore is on an independent parallel 
vein. He gives 3 analyses, of which one is reproduced below 7 . 

Partial analyses of ore from Hampton Knob, Lansing, Ashe County, N. C. 

Silica (Si0 2 ). 0.66 Phosphorus (P).01 

Iron (Fe). 61.58 Phosphorus ratio (P:Fe).016 

Sulphur (S).06 

Openings southwest of Hampton Knob 

Southwest of Hampton Knob other deposits are knowm to be on 
the general strike of those on the knob, but they w 7 ere not visited. 


121 Op. cit., p. 156. 









154 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Nitze 122 states that a quarter of a mile northwest of Dresden which is at 
the junction of Staggs Creek and North Fork of New River, a shallow 
cut on the land of Dr. Wilcox uncovered a 1‘2-foot vein of ore in a gangue 
of hornblende and epidote. The strike of the country rock is N. 60° E. 
and its dip 36° to 40° SE. An analysis of the ore is quoted below. 

Along North Fork and its tributaries from the west the country 
rock of gneiss, epidote and hornblende is described as being “fairly 
charged with crystalline magnetite.” There have been many small 
openings made in the area. Some of these are promising but no deposits 
of value have been found. An outcrop near North Fork, about 2 miles 
south of Solitude, was sampled and analyzed with the result shown: 

Partial analyses of magnetic ore from veins southwest of Hampton Knob, AsheCovnty, A . C. 



Near Dresden 

Near Solitude 

Silica (SiOo). 

. 23.90 

31.22 

Iron (Fe). 

. 52.90 

44.02 

Sulphur (S). 

. . 05 

.058 

Phosphorus (P) . 

. .019 

.004 

Phosphorus ratio (P:Fe). 

. . 036 

.009 


Openings southeast of Lansing 

Veins are known to exist southeast of Lansing that are independent 
of all of those that have been described in its vicinity. On the King prop¬ 
erty, about half a mile southeast of the Ashe Mining Co.'s mine, and 
west of the railroad is an old tunnel on the top of the hill. On its dump 
are banded gneisses that look like mica schists impregnated with gra¬ 
nitic material. In these are layers of magnetite, in some cases as much 
as three-quarters of an inch thick. In other places the magnetite crosses 
the gneiss layers and includes slivers of them. Other fragments are of 
hornblende schist containing lenses of feldspar as though impregnation 
with granite material had taken place. 

A section of the schist reveals the presence of large cellular horn¬ 
blende anhedrons and large grains of feldspar lying in an aggregate of 
small grains of feldspar and a few of quartz and epidote. In the midst of 
this aggregate are crystals and large irregular broken masses of magne¬ 
tite. These are present also in the hornblende. Between the horn¬ 
blende and feldspar is often a mixture of uralite and epidote with narrow 
streaks of pink garnet next to the hornblende. Tiny nests of calcite 
are among the decomposition products, whether they are mainly uralite 
or epidote. Scattered through the matrix are also little nests of calcite 
and quartz. Veinlets of garnet traverse the hornblende and veinlets 
of calcite cut through all parts of the slide. 

Mr. Cooke, who made the opening, furnished an analysis of a sample 
of the ore which showed: iron (Fe) 55.23 per cent and phosphorus (P), 
.0494 per cent. 


122 Op. cit., p. 157. 








MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


155 


Farther east and a little south of the King opening and about a 
third of a mile north of llina, near the railroad but on the east side of 
Horse ( reek, is a tunnel on Mr. Eller’s property. This cut 4 feet of 
ore at its mouth. The ore is in gneiss which near the main ore-bodv 
contains ore streaks rarely more than 1 foot thick. The ore is not 
visibly associated with epidote as it is elsewhere in this district. An 
analysis is not at hand. 


DEPOSITS IN THE NEW RIVER BELT 
General description 

Nitze 123 declares that the New River belt of deposits consists of 
two divisions in distinct and parallel outcrops, lying about half a mile 
apart. The northwestern one, he states, is characterized by a massive 
hornblende-epidote gangue and the southeastern one by a gangue of 
micaceous and hornblendic schists. 

Openings in Alleghany County 

The southeastern division of the belt extends in a broken line about 
S. 70° YV. from a point on Piney Creek in Allegheny County, about a 
quarter of a mile south of the Virginia state line, to New River, which 
it crosses near the Brown opening about half a mile above the falls and 
about miles a little east of north of Crumpler. 

The most northerly opening is on the summit of a hill on the Weaver 
property on the west bank of Piney Creek. The old pits indicate a 
series of veins in a 100-foot wide belt in mica schists (“soft ore”) or 
gneisses (“hard ore“). The dip of the belt is apparently 45° SE. A 
sample of ore, probably of the compact magnetite, gave: Iron (Fe), 
57.31 per cent; sulphur (S), Tr.; phosphorus (P), 0.032 per cent, and 
titanium dioxide (Ti0 2 ), Tr. 

A few hundred yards north of this the country rock is a slightly 
magnetic hornblende-epidote, but there is no distinct ore-body. 

On the land of R. M Halsey on Baldwin Creek, a quarter of a mile 
southwest of the Weaver opening, old workings at the “Hard Bank” 
exposed ores striking N. 60° to 70° E. and dipping 48° to 52° SE. About 
a quarter of a mile farther southwest a tunnel penetrated soft ore in 
mica schists, striking N. 50° E. and dipping 50° SE. 

An analysis of an average sample of the fragments picked from 
the dumps of these various openings gave: Silica (Si0 2 ), 17.81 per cent; 
iron (Fe), 51.62 per cent; sulphur (S), 0.166 per cent; phosphorus 
(P), 0.008 per cent, and titanium dioxide (Ti0 2 ), 0.150 per cent. 


123 Op. cit., p. 133. 



156 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Lunceford openings and Cox place 

Openings between Baldwin Creek and North Fork indicate that the 
southeast division of the belt is nearly continuous between these points, 
but very little is known about the deposits in it. About half a mile 
above the falls of the North Fork a series of shallow pits near the river 
shows the trend of the ore belt to be S. 50° W., but nothing of importance 
is revealed by them, until the Lunceford place is reached. Here, on 
the top of a hill, near the river, are several large openings that have fallen 
in. Nothing was seen in them. Nitze 124 states that the ore body 
measured 13j^ feet at the surface, and that its foot-wall dipped 44J^° 
SE. while its hanging dipped 60° SE. on the average. Both walls were 
mica schists. The ore is a granular magnetite, which at the surface 
was soft, but which became harder and more compact with depth, where 
the epidote increased in the gangue, and the mica schist was confined 
to the walls. 

From this brief description it is difficult to understand why the 
two divisions of the belt are regarded as possessing different characters. 
Epidote, which is said to be peculiar to the northwestern one, was found 
at the Lunceford opening, and the ore was within distinct walls. It 
appears probable that the two divisions are similar and that their appar¬ 
ent dissimilarity is due solely to the facts that in the southeastern div- 
sion the deposits are in mica schist instead of a more resistant rock and 
that the openings are so shallow that they have not reached compact 
ore as in the openings in the northwestern division. 

The southeastern division of the belt recrosses the river at the 
mouth of the stream one mile east of Helton Creek and continues in a 
southwest direction without notable exposures except at the Cox place, 
a short distance west of Grumpier. 

Analysis of average samples of the ore from the Lunceford pit and 
of the float on the Cox place near old Crumpler Post Office, are reported 
by Nitze as follows: 

Partial analyses of ore at Lunceford and Cox places, Ashe County, N. C. 



Lunceford 



place 

Cox place 

Silica (Si0 2 ). 

_ 38.75 

12.50 

Iron (Fe). 

_ 29.95 

48.78 

Sulphur (S). 

_ .144 

.02 

Phosphorus (P) . 

_ .390 

.089 

Phosphorus ratio (P:Fe). 

. 1.302 

. 182 


All the ore in the southeastern line of deposits is plainly of low 
grade, either from the admixture of siliceous material or because of the 
presence of an excessive amount of phosphorus. Moreover, none of the 
deposits are known to be of sufficient size to be worthy of serious con¬ 
sideration from a commercial point of view. 


124 Op. cit.. pp. 134-135. 








MIXES AND PROSPECTS IN SILICEOUS MAGNETITES 


-| ft* 

15 i 

The northwestern division of the belt (here called the Ballon Belt) 
possesses larger concentrations of ore material than the southeastern 
division, but the ore in many of the deposits contains too much phos¬ 
phorus to be of great value. 

Brown openings 

The most northerly openings on the Ballou belt are on the Brown 
farm on the west side of the North Fork at the falls. One of these was 
a cut exposing about 30 feet of ore consisting of gneiss interleaved with 
layers and lenses of hornblende, epidote, and magnetite. An average 
analvsis of the ore is shown in column 1 below. 125 About half a mile 
west of the river is another opening. It is now completely caved, but 
when Nitze visited it he was able to see that it exposed a series of layers 
of mica schist, partly impregnated with magnetite, and streaks of hard 
compact ore—the later about 2 feet wide. Below the floor of the cut 
the ore is reported to pinch out, thus indicating its lenticular habit. 
In column 2 is given the analysis of a washed ore from this pit, and in 
column 3 the analysis of an average sample “taken across the entire 
bed.” The unwashed ore contained 43.5 per cent of iron. 

Partial analyses of ore from the Brown openings, Ashe County, N. C. 



l 

% 

3 

Silica (Si0 2 ). 

24.80 

2.40 

5.73 

Iron (Fe). 

40.04 

67.35 

60.48 

Sulphur (S). 

. 055 

.... 

.003 

Phosphorus (P) . 

. 063 

.028 

.030 

Phosphorus ratio (P:Fe). . . . 

. 132 

.041 

.049 


Ballou Home Place and Sand Bank openings 

The belt crosses the North Fork about half a mile west of the 
Lunceford opening and is exposed in a very prominent outcrop on the 
Ballou Home place on the hill east of the river and opposite U. Ballou’s 
residence. It recrosses the river near M. Ballou’s house and continues 
southwestward as a very distinct vein which has been opened at a num¬ 
ber of places, disclosing one or more large ore-bodies, and, just below the 
house, again crosses the river to its south side. (See Figure 16.) 

At the Ballou Home place on the east side of the river the ore is 
hard, compact, and fine-grained. It is described by Nitze 126 as being 
disseminated through a gangue of hornblende, epidote, and quartz. 
The highest point of the outcrop is 260 feet above the river, in which 
other outcrops can be seen. 

On the west side of the river the vein is exposed in the road north 
of Mr. Ballou’s house; and on the hill back of his house about 200 feet 
above the river it was opened by pits and a tunnel, known as the “Moore 


i25Nitze. H. B. C., Op. cit., pp. 135-136. 
I260p. cit., p. 137. 











158 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

bank.” Here the thickness of the ore is 4 feet. In the tunnel are gneisses 
which are horizontal in some places and which in other places dip south¬ 
east. The rock near the ore is a foliated epidote-hornblende gneiss. The 
magnetite, which is in layers in the gneiss, is near the epidote. Other 
tunnels and pits mark the vein all the way to the river. Much of the 
ore is a mixture of magnetite, epidote and quartz, and in many places 
distinct veins of nearly pure epidote cut it. 


SCALE 

600 


CONTOURS /NTERVAL SORT 
O = R/TS 
C3 = TRENCHES 
□ = CHARTS 

Cl = TUNNEL \S 



WOODLAND 


Figure 16. Map of explorations on the Ballou “Home Place” and the Calloway 
properties, Ashe County, North Carolina. 


The epidote-hornblende gneiss is very much like that at the base 
of Smoky Mountain (see page 111) and elsewhere. It is a fine-grained 
gneissic aggregate of hornblende and epidote interlayered with a coarser 
gneiss of the same composition and with layers of coarse hornblende. 
In thin section the hornblende is seen to be associated with quartz, and 
the epidote to be limited to distinct areas in which there is relatively 
little hornblende. Between the coarser and finer grained gneisses is a 
selvage of coarse hornblende, which apparently has an intrusive contact 
with the finer gneiss. Although difficult to interpret it is possible that 
the specimen represents a hornblende schist that was impregnated with 
pegmatitic material. 















MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


159 


Farther southwest, on the east side of the river, the vein was again 
opened by a number of pits at the “Sand bank” on the Calloway pro¬ 
perty (Figure 16), about one mile S. 35° W. from the Home place. 
There are here 7 or 8 openings but they are now inaccessible. The ore 
is like that on the Home place, but is said to be more sandy and less 
susceptible to concentration. The country rock seen on the dumps is 
a foliated biotite-gneiss, showing no trace of epidote in the hand speci¬ 
men. It is apparently the rock that occurs in several large exposures 
behind the mill at the mouth of Helton Creek where it consists mainly 
of layers of interlocking quartz and orthoclase alternating with others 
composed of individual crystals and groups of grains and crystals of 
epidote, wisps of dark brown biotite, a few of muscovite, and large crys¬ 
tals of apatite. In this are nests of calcite. 

Since Mr. Nitze’s visit the “Home place” property has been ex¬ 
plored by the ^ irginia Iron, Coal and Coke Co., and the Calloway prop¬ 
erty by Mr. Ballou and other parties. Thus the whole vein east of the 
river in the bends northeast and southwest of Mr. Ballou’s house has 
been developed throughout nearly its entire extent, but unfortunately 
the results of the work done by the ^ irginia Iron, Coal & Coke Co. are 
not available. 

The principal openings on the “Home place'' are the Robinson 
opening to the northeast near the top of the hill and the Pine Tree tunnel. 
The latter which is near the base of the hill, runs northeast into the hill 
for a distance of 100 feet to a quartz and pegmatite foot wall containing 
a little pyrite. The ore here is a compact magnetite interbanded with 
mixtures of magnetite and hornblende. It is said to be 22 feet wide, 
dipping between 45° and 50° SE. Near the foot-wall at the Robinson 
opening the ore is a granular magnetite interlayered with an epidote- 
hornblende schist as at Cranberry. The schist is made up of very flat 
elongate lenses of the two principal components. In thin section the 
epidote lenses are found to consist almost exclusively of granular epidote 
or of epidote and small streaks of quartz grains and the hornblende 
lenses of flakes and wisps of dark-green uralite and quartz in about 
equal portions with small crystals of epidote scattered among them. 

The developments on the Calloway property are ivell described by 
Pratt 127 as follows: 

“The iron ore outcrops at the top of the hill, and has been developed by means 
of cuts and tunnels, so that the ore is exposed at various points from the top of the 
hill to the creek, 150 feet or more below. The principal development work on the 
Calloway property is a tunnel that was started about 140 feet below the top of the hill. 
This tunnel was extended in a N. 35° E. direction for a distance of 103 feet, when it 
encountered the iron ore. A crosscut was made in order to determine the width of 
the ore, and it exposed a width along the crosscut of 27 feet 8 inches, which would give 


i2 7 Op. cit., p. 66. 



160 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

a width across the vein of about 20 feet. The strike of the vein is approximately N. 
45° E. The crosscut, after penetrating the ore, was turned N. 70° E., and then GO 0 
W., following the hanging wall until it again encountered the ore, which it followed 
for a distance of 17 feet 8 inches without penetrating the ore body. This gave a hori¬ 
zontal distance of about 30 feet along the vein. ... By means of float and a few 
crosscuts this ore belt can be traced in a southwesterly direction for a distance of about 
a mile across what is known as the Davis property and the Neaves property, when it 
crosses the north fork of New' River. ... On the Calloway property it is estimated 
that there is a distance of 450 feet of the vein from the tunnel to where it crosses onto 
the property owned by the Virginia Iron, Coal and Coke Company. Average samples 
of the ore as exposed in the tunnel were taken across the vein, where cut by the cross¬ 
cuts.” Results of the analyses of these are given below: 

Partial analyses 1 of average samples of ore from tunnel on the Calloway property. 

1 2 

Silica (Si0 2 ). 17.37 38.36 

Iron (Fe). 31.20 

Sulphur (S). .10 .... 

Phosphorus (P) . . 028 .... 

Southwest of the “Sand bank” the belt crosses and reerosses the 
river but is lost as a distinct vein before it reaches Phoenix Mountain. 
About \}/2 miles front Ballou’s it outcrops on the east side of the river 
in a high bluff, but its thickness is only 2 feet. 

• 

The quantity of ore in the Home and Calloway properties can not 
be estimated with the small amount of data at hand. There is no op¬ 
portunity for obtaining measurements of the ore-bodies uncovered be¬ 
cause they are now inaccessible. The explorations on the Calloway 
property seem to prove the existence of several veins, but none of them 
have uncovered wide lenses. On page 80 are given estimates of 350,000 
tons on the Calloway property and 250,000 tons on the “Home place,” 
but they are based on assumptions rather than on known conditions. 
The portion of the vein on the west side of the river is too narrow to 
bear the cost of mining and concentrating. 

RESERVES IN ASHE COUNTY 

So far as can now be determined the onlv areas in Ashe countv 
that are promising as future producers are the Graybeal property and 
the area on North Fork near Mr. U. Ballou’s residence. The conditions 
at these places have been described in some detail. The deposits at all 
the other localities are small and are not close enough together to be 
worked as one operation; consequently they cannot be .regarded as 
available reserves until the price of ore becomes much greater than at 
present. (See also pages 147 to 153.) 


1 Analyst: Frank Tran?. Charlotte, N. C. 








CHAPTER VIII. 


MINES AND PROSPECTS IN SILICEOUS 

MAGNETITES 

DEPOSITS IN THE PIEDMONT AREA OF NORTH CAROLINA 

PRELIMINARY STATEMENT 

Although the magnetite deposits in the Piedmont Plateau of North 
Carolina were known before those in the mountain district and had 
furnished ore to local forges during the War of the Revolution, none of 
them has been developed on as large a scale as at Cranberry and for 
30 years all of them have been abandoned. At several places recent 
explorations have been undertaken to test the sizes and quality of the 
deposits, but in no case were favorable results obtained. Some of the 
ore-bodies are apparently large, but the quality of the ore and the dis¬ 
tance of the deposits from the market prevent their development at the 
present time. 



Fig i ke 17 Map of iron ore deposits in Catawba, Lincoln and Gaston counties, 
North Carolina (part after Kerr, Hanna, and Nitze), 1. Powell mine; 2, Abernethy mine; 
•t Morrison mine- 4 Robinson mine; 5, Stonewall mine; 6, Brevard mine; /, Big Ore bank; 

harrinsrer mine’- 9’ Forney mine; 10, Ormond mine; 11, Little Mountain mine; 12, Costner 
mine- 13, Ellison mine; 14 , Ferguson mine; 15, Fulenwider mine; 16, Yellow Ridge mine; 
17, Crowder Mountain prospects. 
















MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


162 


Only those deposits in Catawba, Lincoln and Gaston counties are 
discussed here. (See Figure 17.) They comprise some of the most im¬ 
portant occurrences in the Piedmont district and are typical of those 
elsewhere in the district. 

The rocks with which the ores are associated are gneisses, schists, 
slates, limestones, quartzites, and granites cut by granite, pegmatite 
and diabase dikes. The schists are known to be in part very much 
sheared volcanic rocks, and in part schistose sediments. These rocks 
occur in a number of approximately parallel belts crossing the State 
from northeast to southwest. They are not all of the same age, but 
their precise age relations have not yet been worked out. They are 
believed by most geologists to be pre-Cambrian. 

In a report on the gold and tin deposits in Lincoln and Gaston 
counties near Kings Mountain, Graton 128 declares that a broad view 
of the field confirms the idea that many of the rocks associated with 
the ores are of sedimentary origin, since they reveal a stratigraphic suc¬ 
cession characteristic of sedimentary formations. 

“Impure quartzites, biotite and sericite schists, and partially marmorized lime¬ 
stones, representing original sandstones, conglomerates, shales and limestones, are 
bedded with true sedimentary regularity. . . . From evidence furnished by the 
structure ... a succession has been determined wdiich is probably fairly correct . . . ” 

“These strata are penetrated or separated by layers of amphibolite lying in 
parallel position. It seems probable that part of the amphibolite represents inter¬ 
calated intrusions into the sediments, while part represents interstratified deposits 
of basaltic tuff or flows of basalt lava. Ancient bodies of granite, now converted into 
a more oi less foliated gneiss are likewise intercalated with the other rocks. More 
recent intrusions of granite, pegmatite and diabase have also penetrated these strata.’ > 

The graphite, manganese and some of the iron deposits are thought 
to be in beds that “represent localized deposits in bogs or swamps.” 

The beds were believed to be in isoclinal folds with NE.-SW. axes 
and steeper dips on their southeast than on their northwest limbs. 

“Because of their comparatively small extent, the beds of iron and manganese 
ore and the conglomerate do not always form continuous outcrops and are (therefore) 
not always present on both sides of the fold.” 

More careful studies of the area confirm the correctness of Graton’s 
general views. 129 

The deposits in Catawba, Lincoln and Gaston counties may occur 
in distinct belts striking for long distances about N. 30° E., but the 
belts in Gaston County are offset with reference to those farther north 
and may not be continuous with them. The northern belts are separated 
from the southern ones by a stretch of country 12 or more miles wide 
from which no ore has been reported. 

128 Graton, L. C., U. S. Geol. Survey, Bull. 293, p. 26, 1906. 

129 Keith, Arthur and Sterrett, D. B., Tin resources of the Kings Mountain district* 
North Carolina and South Carolina: U. S. Geol. Survey, Bull. 660, p. 126, 1918. 




MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


163 


Hanna 130 mapped the area in 1888 (Figure 17), and Kerr 131 in 1875 
declared that at that time of all the iron ore ranges in the State the 
Lincoln county belts were the best known and best developed and had 
been the principal source of the domestic supply of iron for a hundred 
years. 

At one time there were 5 furnaces and several Catalan forges working 
on the ores of the belt—one of the furnaces having remained almost 
continuously in blast for more than 100 years. The iron made was 
regarded as excellent. 132 

ORIGIN 

The magnetic ores in the Piedmont area apparently have a different 
origin from those in the mountain district. They do not occur as lenses 
in distinct veins as does the ore at Cranberry, nor are they associated 
with epidotized pegmatites. On the contrary, they are almost always 
associated with talcose schists and quartzites. Emmons regarded them 
as igneous but noted their close association with quartzites. He writes 133 , 

“The position of the narrow belt of talcose slate in which the ore occurs, is below 
or behind the heavy masses of granular quartz. These masses of quartz, as they are 
continuous from the South Carolina line to the Catawba, are landmarks for the posi¬ 
tion of the ore. . . . 

“The careful consderation, therefore, of such relations is of great importance; 
they furnish a clue to the actual position of the veins. . . . 

“The quartz being a rock easily distinguished, becomes a guide to the position 
of the ore. The limestone is usually west of the beds of ore. The ore is usually near 
the crest of a ridge. ...” 

Lesley 134 , referring to the titaniferous ore of the Tuscarora and 
Shaw belts, which he evidently regarded as having the same origin as 
the non-titaniferous magnetites, states that: 

“The beds were deposited like the rest of the rocks, in water; deposited in the 
same age with the rocks which hold them—are in fact rock-deposits highly charged 
with iron and they differ from the rest of the rocks only in this respect—That they 
are more highly charged with iron. In fact, all our primary (magnetic and other) iron 
beds obey this law." 

The later students of the North Carolina ore have expressed no 
definite opinion as to the origin of the magnetites but inferentially they 
have assumed that they were laid down with their enclosing rock as 
ferruginous beds. Thus Kerr 135 concludes that since the Tuscarora 
and Shaw belts of titaniferous ores approach one another as they pass 
southward, 

i3°Kerr, W. C., and Hanna, G. B., Geology of North Carolina, vol. 2, chap. 2, 

D 155 1888 

liiKerr, W. C., Report of Geol. Survey of North Carolina, vol. 1, p. 251, 1875. 

i 32 Kerr and Hanna, Op. cit., p. 167. 

i 33 Quoted by Hanna from Emmon’s Geological Report of the Midland counties of 
North Carolina, p. 113, 1856. Kerr and Hanna, Op. cit., pp. 156-157. 

134 Lesley, J. P., Note on the titaniferous iron ore belt near Greensboro, North Caro¬ 
lina. An. Philo’s. Soc. Proc., vol. 12, p. 139, 1871. 

i 35 Op. cit., p. 241. 




MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


104 


“it is almost certain that the Shaw belt is the northwest outcrop of a synclinal basin 
3 miles wide, and that the Tuscarora belt is the southeast outcrop,'' and Nitze 136 de¬ 
clares that “the application of the term ‘veins’ is essentially incorrect. They are rather 
ore-beds or ore bodies.” 

No evidence is given by Emmons for concluding that the ores are 
igneous and no evidence is cited by Kerr, Hanna or Nitze to prove that 
they are sedimentary. The only reason suggested for concluding them 
to be sedimentary is the fact that the Tuscarora and Shaw ore belts 
appear to be on the opposite sides of synclinal fold. 

From the nature of the rocks associated with the ores it is evident 
that they comprise an interlaminated series, many of the layers of which 
—the limestones, slates and quartzites—are sedimentary. With these 
are gneisses and schists that are believed to be sheared volcanic rocks. 
Fome of the schists are amphibolites that are supposed to represent in 
part intrusions that were forced into the sediments, and in part inter- 
stratified basalt lava flows or ash deposits. The ore is described as being 
actinolitic, talcose or chloritic schist saturated with magnetite. Since 
actinolitic, talcose and chloritic schists are common metamorphic prod¬ 
ucts of basaltic rocks it is probable that the schists with which the ores 
are associated are old lava flows or tuff beds. If this is the case thev 
must exist as layers with the sediments and are involved in any folding 
to which the series has been subjected. 

Some of the ores are said to occur in beds and layers in the schists, 
others to exist in irregular deposits “with overlaps and jumps; the ore 
giving out at one place and suddenly reappearing at another,” others 
to appear as lenses composed of alternating layers of magnetite and 
talcose schists, in which the magnetite is in thin “strata” of clean ore 
and the talcose schists are impregnated with magnetite in small grains. 
At the Forney mine the ore has been described as being in “irregular 
pockets,” “scattered very disorderly through the massive syenytic 
rock,” which was probably an augite syenite. At Crowders Mountain 
ore-bodies have been stated to occur in the quartz schists comprising 
the elevation, and Hanna relates that often 

“there is a transition from quartzite to ore and vice versa; the extreme terms being 
a quartzose iron ore on the one hand, and a ferruginous sandstone or quartzite on the 
other.” 

He also notes that “some of the ore beds were charged with py¬ 
roxene.” 

At the Fulenwider mine there are exposures of talcose quartz 
schist cut by veins of quartz and tourmaline (see page 180.) In some 
places the tourmaline replaces the quartz of the veins. As the veins 
are parallel to the bedding of the quartz schist the result is a series of 


13 «Op. cit.. p. 2<q 




MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


165 


schists interlayered with seams of tourmaline, resembling the layers of 
ore in the quartz rocks elsewhere. At intervals the tourmaline layers 
swell to a foot or more in thickness, forming rude lenses. 

The talcose schist is probably a sheared igneous rock. Its compo¬ 
sition suggests that it is igneous rather than sedimentary and its nature 
is identical with that of similar schists elsewhere that are known to be 
sheared igneous masses. Its occurrence at a constant horizon in a series 
of sediments, always very near a heavy bed of quartzite, suggests that 
it was originally a lava flow, a sill, or more probably, a tuff. From the 
descriptions of those who have seen the ore in place, this is said nearly 
always to be associated with the talcose schist. But in a few places 
magnetite is in quartzite or quartz schist, apparently replacing the quartz, 
and at one place tourmaline exhibits similar relationships. In the 
talcose schist the magnetite appears to be in distinct veins, as well as in 
lenses, and in some places to be disseminated as crystals through the 
schist. 

The only possible conclusion as to the origin of this magnetite seems 
to be that the ore mineral is a result of hydro-thermal processes, like 
those that gave rise to the tourmaline at the Fulenwider mine, and to 
the rich ore in the Cranberry vein that occurs in vein-like masses cutting 
the lean ore and in the strings of magnetite connecting the ore lenses. 
In the Piedmont the solutions found easier access along the tuff beds 
than through the quartzites and consequently the ore deposits are more 
frequently in the talcose schists than elsewhere. In some places the 
solutions contained boron and made tourmaline. In others they at¬ 
tacked the quartzite and replaced the quartz by magnetite, but usually 
the ore mineral was deposited in the tuff as distinct veins. Although 
marble is one of the members of the sedimentary series with which the 
ore is associated, there is no place known at which the carbonate is 
replaced. This may, perhaps, be due to the fact that the ore and the 
tuff deposit in which most of the ore occurs are both the result of the 
same igneous episode and that igneous action had ceased before the 
limestone had been deposited. 

RESERVES 

Any successful attempt to estimate the available tonnage of magnetic 
ore in the rocks of the Piedmont area is prevented by unsurmountable 
difficulties. Undoubtedly there is an enormous quantity of ore in the 
aggregate, but this is so distributed that it is not generally available for 
commercial purposes because only at a comparatively few points is it 
in large enough ore-bodies to warrant exploitation. The Catawba-Iron 
Station belt was once mined extensively, but at no point on it is there 
evidence of the existance of any large lens of ore. The ore is described 
as being in veins from 2 to 20 feet wide, interlayered with schist. In 
the old mines this was taken out to water level and then the mines were 


106 MAGNETIC IRON ORES OF FAST TENN. AND WESTERN N. C. 

abandoned. There is unquestionably considerable ore in the downward 
extension of these old workings, but whether it is concentrated in suf¬ 
ficiently large deposits to be worked to advantage under present eco¬ 
nomic conditions is doubtful. Moreover, in the descriptions of some 
of the deposits attention is called to the fact that the ore is contaminated 
more or less with pyrite, and that this component increases with depth. 
In some place, below the water level, where it has been protected from 
oxidation, it occurs in large enough quantity to be seriously objection¬ 
able. One of the most promising of the old mines has been explored in 
recent years with a view to reopening it, but the quantity of pyrite 
found in the ore at moderate depths below the present bottom of the 
mine was so great that the place was abandoned. Of course, it is possible 
that some of the deposits are free from pyrite, and that their ore is of a 
desirable quality even at some considerable depth, but though this be 
the case, there is no deposit now knoAvn anywhere in the area which is 
comparable in size with some of the deposits in the mountain district. 
In no case can the ore of any deposit now known be placed on the market 
without concentration. In the future there is no question but that much 
of the ore will be mined, but this will probably not happen until the 
deposits in the mountain district have been thoroughly developed. 

CATAWBA AND LINCOLN COUNTIES, N. C. 

GENERAL DESCRIPTION 

Of the three belts of magnetite in these two counties, the most im¬ 
portant one, which is the central one, extends northeast from Iron 
Station on the Seaboard Air Line Railway, a few miles east of Lincoln- 
ton, to near Catawba on the Southern Railway, a distance of about 20 
miles. The deposits are described as being in “talcose, micaceous, and 
quartzitic schists.'’ A second belt that once contained several mines 
crosses the Carolina and Northwestern Railwav between Newton and 
Maiden. The distance* between the deposits at its two extremities is 
6 miles, but the belt may extend southwest into Lincoln county, a further 
distance of about 10 miles, though it has not been traced this far. The 
deposits are described as being in a “granitic and hornblendic gangue.” 
The third belt is in micaceous schists. It lies about 4 miles east of the 
main belt, and is about 8 miles long so far as traced. The belt is identi¬ 
fied mainly by float. 

DEPOSITS IN THE CATAWBA-IRON STATION BELT 

The series of deposits comprising this belt was formerly among the 
most important in the State. In the early portion of last century it 
was more or less extensively developed throughout its entire extent. 
The large openings still visible at many points give evidence of the 
magnitude of some of the operations. Unfortunately, however, most 


MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


167 


of the work done was by means of open cuts, which are now so filled that 
they furnish no possibility for study. About all that can be done at 
present in the study of the deposits is to examine carefully the descrip¬ 
tions that were written at the time the mines were being worked and 

inteipiet them in the light of present knowledge of similar deposits 
elsewhere. 

In their report on the iron ores of North Carolina Kerr and Hanna 137 
wrote with reference to the magnetites of this belt: 

The beds are nearly vertical and dip sometimes to the east and sometimes to 
the west, but the westerly dips are by far the most frequent. ... For a considerable 
part ol the belt in Lincoln county there are two parallel beds, the more westerly being 
tht more productive, and the combined thickness being from 4 (rarely so low as 2) to 
12 feet, the interval oi 12 to 20 feet between them is occupied by talcose and chloritic 
schists, with a little ore in layers. . . . The beds generally occur in lenticular masses 
or flattish disks, which thicken at the middle and thin out towards the edges, having 
the same general dip as the bed; but they do not succeed one another in the same plane; 
their edges overlapping so as to throw the upper edge of the lower disk behind the lower 
edge of the upper.” 

The following is an ideal section, illustrating this: 

“A, sandstone or quartzite. B, talcose schist (slate). C, ‘Front’ ore bed of 
actinolitic, chloritic, and somewhat talcose schists, containing ore bodies. D, talcose 
and chloritic schists, containing small quantities of ore, mostly in grains. E, ‘Back’ 
ore bed, for most part similar to C. F, talcose schist. G, gneiss. 

“The above-mentioned layers shade into one another; thus the sandstone or 
quartzite, A, passes into the siliceous talcose schist, B, which in turn graduates into 
the ‘front’ vein, C—a mass of actinolitic, chloritic (somewhat talcose) slate, with iron 
ore in grains or in lenticles. The change from the slates into the ore lenticles is fre¬ 
quently obscure, and the lenticles themselves are often schistose in structure. The 
change into the talcose slates (D) is equally obscure. In this body the ore is in grains, 
associated commonly with the chloritic matter, or in small lenticles. 

“The statements about C apply for the most part to the ‘back’ vein, E. 

“The changes into and from F are as in B, but the mass seems to be less siliceous. 
The separation of the ore bodies is sometimes very slight, and often they are con¬ 
nected by an almost imperceptible thread of ore, which needs the quick eye of the skill¬ 
ful miner to follow. These lenses are sometimes many feet thick, and frequently of 
great length and depth." 

The deposits on this belt that were formerly worked are designated 
by Nitze 138 , beginning with those to the north: the Powell, Littlejohn, 
Abernathy, Mountain Creek, Deep Hollow, Tillman, and the Morrison 
banks in Catawba county, and the Robinson, Stonewall, Brevard and 
Big Ore banks in Lincoln county. Besides, surface exposures and float 
are visible at several points between these old mines, and at two points 
south of the Big Ore bank. Unfortunately, as has been stated, all the 
openings have become filled so that nothing can be learned from them 
at present. 

i 37 Kerr, W. C., and Hanna. G. B., Ores of North Carolina: Geol. of North Carolina, 
vol. 2, chap. 2, p. 157, 1888. 

138 0p. cit., p. 90. 



168 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

Powell ore bank 

The Powell ore bank is about 43^ miles southeast of Catawba on 
a little hillock on the southside of Ball Creek, on property now belonging 
to Albert Kale. The entire top of the hillock is honeycombed with many 
small pits, and several old shafts. On the dumps are a few fragments 
of rusted magnetite, and in the fields around the hillock are abundant 
fragments of quartz schist. There is nothing to indicate whether the 
ore is in the schist or not. Nitze states 139 , that the mine was worked 
from 1873 to 1875. Kerr and Hanna 140 , declare, “the beds of ore are 



Figure 18. Ideal section illustrating lenticular shapes and positions of magnetite 
ore beds, Lincoln county, N. C. (After G. B. Hanna.) 

numerous and quite irregular, with overlaps and jumps; the ore giving 
out at one place and suddenly reappearing at another. The main bed, 
opened to a depth of 30 feet by a shaft, is at that depth from 3 to 4 feet 
thick, with a strike N. 10° E., and a dip westward from 60° to 90°. 
On a para 1 lei hill a quarter of a mile northwest of the above is a similar 
ore bed. The same series of beds is exposed one mile south-southwest 
from the Powell bank, at the Littlejohn ore bank.” 

x4n analysis of the ore, quoted by Nitze, resulted as follows: Iron 
(Fe), 64.21 per cent and phosphorus (P), 0.009 per cent. 

Little Mountain deposits 

The deposits in Catawba county between the Powell bank and the 
northern end of Anderson Mountain were not visited, but since no in¬ 
formation as to their locations could be obtained from the farmers in 
their vicinity it is assumed that their openings have disappeared. How¬ 
ever, on the east slope at the north end of Little Mountain, which is 
the local name for the northeast peak of Anderson Mountain, there are 


“•Op. cit., p. 93. 
U0 Op. cit., p. 167. 



MINES AND PROSPECTS IN SILICEOUS MAGNETITES . 169 

? or 8 large pits and several long trenches that have uncovered a great 
deal of ore, but none could be seen on dumps. It is reported by men 
who worked in the mine, which is known as the Paine and Smith mine, 
that there was also a shaft on the property that was 100 to 150 feet deep. 
The crest of the hill to the west is quartzite. About \}/± miles to the 
southwest is a bed or lens of graphite schist associated with talc schist. 
It h as been opened up as the Caldwell mine. 

About three-quarters of a mile farther west is a belt of interlayered 
white and blue marble with a layer of quartz between, exposed in the 
bed of a branch of the south fork of Mountain Creek, a few yards west 
of the road leading south from Pisgah Church. The analyses of samples 
taken from 3 quarries on the belt are reported by Nitze 141 to be as fol¬ 
lows : 


Partial analyses of marble from near Pisgah Church, Catawba County, N. C. 


Shuford quarry, 5 miles south of Catawba . . . 

Si02 

1.28 

FeaOs. AI 2 O 3 
3.17 

CaO 

33.18 

MgO 

19.07 

Powell quarry, 4 miles south of Catawba .... 

2.60 

1.54 

34.27 

20.09 

Keener quarry, 6 miles northeast of Lincoln ton 

. 45 

4.46 

35.90 

17.63 


About half a mile to the northwest and a quarter of a mile south 
of Pisgah Church the fields are covered with fragments of rusty mag¬ 
netite. This is probably just east of the marble. 

Whatever the origin of the ore at Little Mountain, it is evident that 
it is associated with sedimentary rocks. Whether the workings are 
those of the old Abernethy mine or not was not determined. The na¬ 
tives seem to have no remembrance of any mine of this name. 

Anderson Mountain openings 

The Little Mountain ore veins extend across the county line. They 
are described by Nitze as occurring east of Anderson Mountain and at a 
number of points south of Sanders Mills in Lincoln county. The open¬ 
ings at the Mountain Creek, Deep Hollow, Tillman, and Morrison 
banks were not visited, but none of these operations was ever important. 

South of the county line in Lincoln county the openings were much 
more important. In order they were the Morgan, Stonewall, Brevard 
and Big Ore banks. Of these the Big Ore bank was by far the most 
extensive. Only this one was visited as the openings at the others have 
nearly disappeared. 

Morgan and Stonewall banks 

Of the old Morgan bank little is known. The Stonewall bank was 
mainly a prospect. Nitze 142 reports that two shafts were sunk on the 
property, which is about half a mile south of the county line. The depth 
of one of these was 64 feet and of the other 72 feet. Cross cuts driven 


141 Op. cit., p. 94. 
142 Op. cit., p. 92. 



170 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

from near their bottoms penetrated an 8-ineh wide vein of “reddish 
talcose ore," and two veins of “gray ore.’’ An analysis of a sample, 
presumably of the gray ore, gave: 

Iron (Fe), 55.40 per cent, and phosphorus (P), 0.011 per cent. 

Brevard and Big Ore banks 

Southwest of the Stonewall bank are the Brevard and the Big Ore 
banks, on a continuous vein, the Brevard property lying immediately 
north of the Big Ore property. The old shafts on both properties have 
disappeared and the pits have fallen in, so that nothing can be seen of 
the method of occurrence of the ore. 

The openings of the Big Ore bank are on both sides of the road 
between Macedonia Church and Derr in the Hickory quadrangle. 
The series of openings, which include some immense holes, crosses the 
road about half a mile southeast of the road junction at Macedonia 
Church in a belt about 250 to 750 feet wide, striking N. 25° E., and ex¬ 
tending from a point one-third of a mile north of the road to a point a 
few hundred yards north of the south edge of the quadrangle, a distance 
of about l l 4: miles. A map of the development at the time the Tenth 
Census was taken is reproduced in Figure 19. 

On the dumps were found a few pieces of rusty magnetite and frag¬ 
ments of foliated rock composed of alternating layers of chlorite, mica 
schist, and fine-grained gneiss. A similar rock was seen in exposures at 
a little falls just west of the westernmost line of pits. About 250 feet 
west of the westernmost pits on the north of the road are exposures of 
coarse quartzite. Both the schist and the quartzite are apparently 
under the ore, with the quartzite beneath the schist. 



Figure 19. Sketch map of openings at the “Big Ore Bank” in Lincoln county, North 
Carolina. (After JIailey Willis.) 


In the description of the mine in the Tenth Census report, it is 
stated 143 on the authority of an old miner, that the ore 

“lies in lenticular masses, which overlap each other, the southern end of one lying 
west of the northern end of the next. These ore bodies consist of alternate la; ers of 

l43 10th Census U. S., vol. 15, p. 317. 









MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


171 


magnetite and talcose schist, and have a thickness of 8 to 20 feet, with a maximum 
length stated at 80 feet. The greatest thickness of any one stratum of clean ore is 
perhaps 2 feet; but such a layer is usually between two thinner ones of talcose schist 
impregnated with ore, so that the entire thickness would be mined out at once. As 
the strata stand nearly vertical there are apparently several parallel lines of ore bodies.” 

At the engine shaft the thickness of the mass of ore opened was 
16 feet. This was mined in 1880-1882. The shaft was 100 feet deep, 
and, according to Nitze 144 , a cross-cut at its bottom went through 60 feet 
of alternating schists and ore, as indicated by a sketch which was “drawn 
according to verbal statements obtained from Mr. J. E. Reinhardt, the 
last superintendent and manager of this mine.” The foot-wall according 
to Nitze was a schist and the hanging-wall a “metamorphic sandstone,” 
but this applies rather to the series of ore and schist layers that constitute 
the ore-bodv, than to the individual ore lavers. There are three ore 
layers shown in the figure, and these are separated by layers of schist. 
Of these two are of “gray ore,” which is a schist through which is dis¬ 
seminated granular magnetite, and the third of “red ore” which is com¬ 
posed partly, perhaps, of martite. 

Analyses of these two varieties are recorded by Nitze. They are 
as follows: 

Partial analyses of ore from Big Ore bank, Lincoln County, N. C. 



Gray ore 

Red ore 

Silica (Si0 2 ) . 

.... 6.19 

1.07 

Iron (Fe). 

.. . 66.92 

68.40 

Sulphur (S).. 

.... .068 

.069 

Phosphorus (P) . 

. . . . .082 

.072 

Phosphorus ratio (P:Fe) . 

_ .124 

. 105 


The complete analysis of a sample taken from the shaft marked 
with an X in Figure 19, at a depth of 40 feet, is quoted from the Tenth 
Census Report. 145 A is the analysis of the entire sample and B that of 
the portion insoluble in acid. 

Analysis of ore from the Big Ore bank, Lincoln County, A. C. 


A 13 

Silica (SiCL). 9.14 9.14 

Iron peroxide (Fe^th) . 73. G7 . . . . 

Alumina (AI 2 O 3 ) . 2.45 1.83 

Iron protoxide (FeO). 8.68 

Manganese protoxide (MnO). -06 . . . . 

Magnesia (MgO). 4.32 3.17 

Lime (CaO). • ^7 .20 

Iron disulphide (FeSa). -14 .... 

Copper sulphide (CuS). -05 

Carbonic acid (CO 2 ).. • 

Phosphoric acid (P2O5) . -03 


Carbon in carbonaceous matter 
Water of composition (H 2 0-h) 
Hygroscopic water (H 2 0). 


144 Op. cit., p. 91. 

145 10th Census U. S., vol. 15, p. 317. 


100.25 





























172 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Insoluble siliceous matter. 14.32 14.34 

Iron (Fe).. 58.38 .... 

Phosphorus (P). .013 

Phosphorus in 100 pts. iron (P:Fe). .022 


Deposits near Iron Station 

No evidences of the presence of the vein between the Big Ore bank 
and the vicinity of Iron Station have been recorded. Aitze 14fi reports a 
heavy showing of float ore and some old pits 1miles northwest of Iron 
Station and a quarter of a mile north of the railroad. Ore was taken 
and hauled from the pits to a local forge about 75 years ago. About a 
quarter of a mile southwest of the railroad float ore is again encountered, 
and it is reported that ore was dug here also for the local forge. 

No trace of the belt has been found farther to the southwest unless 
that on which the Costner mine in Gaston county is situated is its con¬ 
tinuation. If this is the case the vein has been displaced several miles 
in the interval. 


DEPOSITS IN THE NEWTON BELT 

The line of deposits mapped by Nitze as passing between Newton 
and Maiden has not been traced continuously for any great distance. 
Consequently there is no evidence that the various deposits are actually 
on the same vein. It is mapped as running from the Barringer mine 
east of Newton to the Forney mine southwest of Maiden and as reappear¬ 
ing again 5 miles farther southwest on Howards and Indian creeks in 
Lincoln County. 

Only 3 mines have been opened on the supposed vein—the Barringer, 
the Forney, and the Killian mines. The last two are referred to in the 
Tenth Census Report as existing in Kerr’s “syenite belt." The Bar¬ 
ringer mine is not mentioned. Nitze places all of them in a “hornblende 
belt,” which, however, in his ideal cross section is designated “syenite.” 


Barringer mine 

The Barringer mine is about l z /£ miles a little south of east of New¬ 
ton just north of the main highway leading east. The mine is now 
represented by a dozen holes lying in a row striking a little east of north. 
Some of them have recently been reopened. Several are at least 20 feet 
deep and some of these are extended underground by short tunnels. 
The old dumps contain nothing but red clay and a few fragments of 
rotted magnetite. East of the pits the fields are full of fragments of a 
schistose quartzite containing considerable muscovite. Thin sections of 


ue Op. cit., p. 90. 







MINES AND PROSPECTS IN SILICEOUS MAGNETITES 173 

this rock reveal only large and small interlocking quartz grains, pierced 
hv large flakes of colorless muscovite, and here and there an occasional 
fledspar grain. Many of the quartzes are cracked and some are crushed. 
Nearly all exhibit strain shadows. 

Kerr 147 writes that the vein is nearly vertical and that the ore is a 
compact, or a coarse, granular magnetite, nearly free from gangue 
which is granitic, and that formerly it was hauled 15 miles to mix with 
local brown hematite for use in a forge. During the Civil War several 
thousand tons were mined. The ore outcrops a quarter of a mile north¬ 
east of the mine in a gully alongside a road, but has not been traced 
farther northeast or southwest. 


Forney and Killian mines 

The Forney mine is about 1 mile southwest of Maiden. The open¬ 
ings are in a woods south of the road leading west from the railroad and 
about 300 yards east of the first forks. The old dumps have rotted to 
a red clay in which are a few fragments of a dense pure magnetite. Ore 
is exposed in a gully on the south side of the road about 300 yards west 
of the mine holes, but there are no other rocks in their immediate vicinity. 

About half a mile northwest of the mine are openings on another 
vein that has been traced for a quarter of a mile. Some of the openings 
are large and have probably yielded considerable ore. They are referred 
to by Nitze as being on the Bost and Williams farms. 

Rock exposures between these openings and those of the Forney 
mine are phases of the Roan gneiss—at any rate they are dark, slightly 
schistose rocks, some of which resemble schistose diabases and others 
basic granites. 

A section of one of the rocks shows that it is composed mainly of 
augite, plagioclase and quartz. The augite, which has nearly disap¬ 
peared, is represented by large cellular masses of hornblende that con¬ 
tain here and there nuclei of pyroxene, and which are full of quartz in¬ 
clusions. The plagioclase is now represented by great irregularly 
shaped masses of cellular garnet, a few quartz grains and numerous 
interwoven prisms of a light colored epidote. The epidote, quartz and 
garnet occupy the areas that were once occupied by the feldspar. In¬ 
deed a small quantity of a fresh, striated feldspar still remains in the 
interiors of some of the garnet-epidote groups, and these are pierced by 
epidote prisms. The larger epidote prisms, like the garnet grains, are 
cellular and they contain quartz inclusions. In the hornblende and the 
garnet a few irregular masses of magnetite are present. They appear 
to be original. 


147 Op. cit., p. 253. 




174 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Most of the quartz in the rock was produced by metasomatic altera¬ 
tion of plagioclase, but some of it is in large anhedrons that may be 
primary. The slight evidences of the original texture of the rock that 
remain suggest that it was granitic—probably a quartz-augite diorite. 

At the time the report of the Tenth Census 148 was written no work 
below 20 feet had been done at either the Forney or the Killian mines, 
although at the Forney mine there was a line of shafts extending 400 
yards in a direction a little west of north. The Killian bank was [referred 
to as being 2 miles west of the Forney mine, but no description of it is 
given. It is stated, however, that the ore at both mines occurs in “irre¬ 
gular pockets, a few inches to 3 or 4 feet thick, and of very uncertain 
length and depth.” Kerr 149 had previously noted that the pockets are 
“scattered very disorderly through the massive syenytic rock.” Analyses 
of the ores of the two mines were made by the chemists of the Tenth 
Census. The sample from the Killian bank was from 4 tons of freshly 
mined ore and that from the Forney bank was taken from a pocket 3 
feet thick. A third analysis is quoted from Nitze 150 , who states that the 
Forney vein has been traced 1 mile. At the depth of 28 feet the deposit 
in one shaft was a coarse granular ore, 4 feet thick. 


alyses of ores from the Forney 

and Killian 

Killian 

ore-bank 

ore banks, 

Pocket in 
Forney 
ore-bank 

Catawba Co 

Forney 

mine 

Silica (^siCE) . 


.... 

1.41 

Iron (Fe). 

64.92 

64.96 

67.92 

Sulphur (»). 

. .... 


.07 

Phosphorus (r). 

. 036 

.009 

. 025 

Phosphorus ratio (r :i e) . . . . 

. 055 

.014 

.036 

Titanium dioxide (TiCh). . . . 


.... 

1 .60 


It is probable that the deposits at the Forney and Killian banks 
and on the Bost and Williams farms are not all on the same vein, unless 
this has been twisted in a way that is not common for the magnetite 
veins of North Carolina. More likely they are small lenses scattered 
through a comparatively wide ore-bearing zone of dark shists. That 
schists may be folded is quite probable, but that they are as complexly 
folded as would be necessary to explain the distribution of the ore-bodies 
on the supposition that they are all on the same vein is improbable, in 
view of the known method of folding in this portion of the iron-bearing 
area. 


Exposures on Howards and Indian creeks 

It has already been stated that there is an interval of 5 or 6 miles 
on the projected strike of the vein to the southwest of the Forney mine 
before other indications of its presence are noted. Float ore on Howards 


148 10th Census U. S., vol. 15, p. 316. 
14S Op. cit., p. 253. 

150 Op. cit., p. 113. 











MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


175 


and Indian creeks indicated to Nitze 151 , that the vein passes southward 
about 3 miles west of Lincolnton. The ore at the southern exposures 
contains small quantities of titanium like that of the Forney mine. 
An analysis gave: Silica (Si0 2 ), 11.37 per cent, iron (Fe), 56.95 per 
cent, sulphur (S), 0.045 per cent, phosphorus (P), 0.029 per cent and 
titanium dioxide (Ti0 2 ), 2.40 per cent. 

DEPOSITS IN THE EASTERN BELT 

The third belt of magnetite deposits in Catawba and Lincoln 
counties is a short and undeveloped one lying 5 miles east of that on which 
the Big Ore bank is located. Nitze 152 describes it as lying in micaceous 
schists, and as having been explored superficially at intervals. At 
McClure Knob, near McClure Bridge, crossing Leepers Creek, the 
distribution of heavy magnetite float on the surface points to the exist¬ 
ence of two fmrallel veins about 500 feet apart, striking N. 15° E. These 
have been followed 13 ^ miles to the southwest, but neither has been 
opened. About 3 miles farther northeast on the waters of Anderson 
Creek, two prospect shafts cut ore which Nitze declares is on the same 
belt; although it has not been traced through the interval. In one 
shaft the ore widened from 15 inches at the surface to 2 feet at the depth 
of 40 feet. In the other shaft, at a depth of 16 feet the ore was only 10 
to 12 inches thick. The ore is described as “a slaty magnetite, which 
breaks easily into large and small rhomboidal blocks." The dip is 
nearly vertical, and the “walls and gangue are mica-schist." 


GASTON COUNTY, N. C. 

GENERAL STATEMENTS 

Some of the ore veins of Lincoln County may extend southwestward 
into Gaston County, but if so some others have disappeared in their 
southwesterly extension and new ones, not represented in the northern 
county, have taken their place. A limestone belt and a belt of man- 
ganiferous slates have been found in Gaston County and they have been 
assumed to be the extensions of similar belts farther north. Since, however, 
there may well be several belts of both limestone and manganiferous slates 
in the district, it is possible that those in Gaston County are not the con¬ 
tinuations of those to the north. This view is rendered the more probable, 
as only one belt of ore deposits is known to exist between the slates and 
limestones in Lincoln County, whereas between the slates and limestones in 
Gaston County there are three belts—one of magnetic ore deposits and two 
of limonite deposits. Moreover, there is a series of limonite deposits west 


isiOp. cit., p. 114. 
i'2Qp. cit., p. 95. 



176 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

of the limestone in Lincoln County and no evidence of such a belt in 
Gaston County. Until the geology of the district is mapped in detail 163 
the relation of the belts in the two counties cannot be determined. It may 
be that when all the ore belts in both counties have been discovered, we 
may find them equal in number and may then correlate them. At 
present it would seem better to consider the southern belts as being 
independent of the northern ones. 


DEPOSITS IN THE EASTERN BELT 
Crowders Mountain deposits 

The easternmost belt of magnetites in Gaston county corresponds 
in position to the easternmost belt to the north, and like this it lias been 
opened at only a few .places. An outcrop of magnetite occurs on the 
northern end of Crowders Mountain about 350 feet above the level of 
Crowders Creek. The vein is described by Hanna 154 and* by Nitze 155 
as consisting of 12 feet of hard, siliceous, magnetite ore containing minute 
particles of garnet. Its analysis is quoted below. 

Another deposit, exposed by an open cut near the crest of the ridge, 
measures 5 feet in thickness. It strikes N. 35° E. and dips 70° to 80° 
NW. “The ore is a gray magnetite in a gangue of white, decomposed 
feldspar.” Its analysis is also quoted. 

In the tenth Census Report 156 an outcrop of coarsely granular mar- 
tite is described as occurring near the summit of the ridge. It is exposed 
on the southwest slope of the mountain. It may be the same deposit 
as that referred to by Nitze. Its partial analysis is shown in the third 
column. 


Partial analyses of ore f rom Croicders Mountain. 


Northern 


end 

Silica (SiCK). 47.11 

Iron (Fe). 31.62 

Phosphorus (P). . 087 

Titanium dioxide (TiC^). .00 


Crest Outcrop 

24.90 _ 

52.08 50.39 

.033 .02 

• 00 


Other deposits of magnetite or martite are said to be present on the 
mountain but their exact positions are unknown. Evidently all of the 
deposits are relatively small and none offer promising prospects at the 
present time. From the descriptions the deposits seem to be scattered 
and there is no evidence that they are on a well-defined vein. 


That the Crowders Mountain quartzite contains many ore bodies 
admits of no doubt. Besides the magnetite deposits mentioned there are 


I53 Messrs. Keith and Sterrett have mapped the area for the U. S. Geological Survey 
but the results of their work have not yet been published. 

154 Kerr, W. C., and Hanna, G. B., Op. cit., p. 166. 

155 Op. cit., p. 108. 

156 10th Census U. S., vol. 15, pp. 320-321. 







MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


177 


several deposits of limonite referred to by Messrs. Willis 157 and Nitze 158 
and several layers of martite schist containing 50 per cent of metallic 
iron. It is probable that most of them are local phenomena and of 
little promise as sources of ore. 

In a footnote to his description of the Crowders Mountain ore beds 
Hanna 159 writes: 

“The iron ore is frequently seen in boulders, one of which was judged to weigh 
200 tons. Most of the ore seemed to be in layers of quartzite or schist, and often there 
is a transition from quartzite to ore and vice versa ; the extreme terms being a quartzose 
iron ore on the one hand, and a ferruginous sandstone or quartzite on the other. Some 
of the ore beds were charged with pyroxene, while others showed the mammillary or 
cellular structure, originally due to its deposition as bog ore.” 

The last statement is evidently intended to apply to the limonites, 
but the correctness of the inference is doubtful, since if the sandstones 
associated with the ore have been metamorphosed to. quartzite and to 
eyanite schist, as Hanna says is the case, any bog ore interlaminated 
with the sandstones would have lost all of its original structure, parti- 
cularlv its cellular texture. 

DEPOSITS IN THE COSTNER MINE BELT 

The most important belt of magnetite in Gaston County is that ex¬ 
tending from the Costner mine northeast of Bessemer City to the Yel¬ 
low Ridge mine about a mile west of the southern end of Crowders Moun¬ 
tain. No deposits have been reported on the belt northeast of the 
Costner mine nor southwest of the Yellow Ridge mine, but between the 
two the vein has been traced nearly continuously and has been worked 
at 3 points. 

Costner mine 

The Costner mine is now a series of nearly obliterated pits, some of 
which were very large. They are situated about miles northeast of 
Bessemer City in the woods. Their dumps are so weathered and in 
some instances so completely covered with verdure that only here and 
there can a fragment of rock be recognized. Kerr 160 describes the rock 
associated with the ore as “granitic and syenitic," and one wall, he 
says, is a bed of crystalline limestone, 12 feet thick. 

“The ore is a very dense, metallic and subcrystalline magnetite, and is very free 
from impurities . . . and the bar iron made from it is ^er\ tough and strong. Ihe 
vein is ten to twelve feet thick; and it is reported by the miners who last penetrated 
it, at a depth of over 100 feet, to be above 20 feet thick." 

15710 th Census U. S., p. 320, 1886. 

i58North Carolina Geol. Survey, Bull. 1, pp. 108-110, 1893. 

is»Kerr, W. C., and Hanna, G. B., Op. cit., p. 166. 

noKerr. W. C., Op. cit., p. 255. 







178 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

A few years later Hanna 161 adds, that the vein strikes N. 10° to 15° 
E. and its dip is nearly vertical, and that it averages 10 feet in width. 

In the Tenth Census Report 162 , it is stated that during the Civil 
W ar a shaft was sunk on the property to a depth of 115 feet. This en¬ 
countered a vein that is reported to have been 7 feet wide. Two kinds 
of ore were obtained but their relations to each other were not ascer¬ 
tained. Analyses of specimens picked from the dumps gave: Iron (Fe), 
51.75 per cent and phosphorus (P), 0.002 per cent for the ordinary ore 
and iron (Fe), 44.per cent and phosphorus (P), 0.004 per cent for 
the “flint" ore. 

Nitze 163 records two analyses of fragments picked from the dumps, 
but he does not accurately describe the specimens. 

Ellison mine 

The next point to the southeast at which ore was mined is the 
Ellison mine, the location of which is described in the Tenth Census 
Report 164 as about 4 miles southeast of the Costner mine, about half a 
mile south of the railroad, and 50 feet from the road between Kings 
Mountain and Dalis. It was probably on the road from Bessemer City 
to Abernethy Creek, but no mine holes were found north of the stream 
over which the road crosses before reaching the main creek. The Census 
Report states that, 

“the greatest depth reached at this bank is 112 feet, and the vein varied from 5 to 12 
feet in thickness, with an average of 7 or 8 feet. The outcrop has been removed for 
about 100 yards.” 

A sample composed of small pieces picked from the dump gave iron, 
54.61 per cent and phosphorus, 0.016 per cent. Hanna 165 reports that 
the “ores are granular magnetites, more or less intermixed with hematite 
of great purity and richness," and that the country rock is actinolite 
schist. 

The anlvsis of a sample of float ore, according to Nitze 166 , yielded 
69.87 per cent of iron and 0.006 per cent of phosphorus. 

Ferguson mine 

The Ferguson mine is not described in the reports of the Tenth Cen¬ 
sus, but in Nitze's bulletin it is referred to as adjoining the Ellison mine 
on the southwest. A visit to the locality revealed a number of pits and 
old shafts in a field on the west of the road crossing Cooper’s Branch, a 
small stream flowing into Abernethy Creek from the north, and two pits 

I61 Kerr, W. C., and Hanna, G. B., Op. cit., pp. 160-161. 

162 10 th Census U. S., vol. 15, p. 318. 

I63 Op. cit., p. 105. 

161 10th Census U. S., vol. 15, p. 318. 

165 Kerr, W. C., and Hanna, G. B., Op. cit., p. 161. 

166 Op. cit., p. 105. 



MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


179 


on the east side of the road in a young forest on the top of a ridge. The 
pits east of the road are about southeast of those on the west side and are 
evidently on another vein. No rocks are in view at any of the pits and 
it is difficult even to discover fragments of ore on their dumps. The ore 
fragments found are of a granular, porous magnetite and of a sandy 
variety. It is likely the ore was originally a mixture of hornblende, 
magnetite and a little quartz. As a result of weathering the hornblende 
has been decomposed and the ore, as a consequence, has become porous 
and sandy. Kerr 167 state's that the ore “is a granular magnetic ore, 
with much iron pyrites, which has been superficially changed to limo- 
nite.” 

Nitze 168 describes the mine in some detail. He states that the ore 
was a compact magnetite that was worked about the middle of last 
century by open cuts and tunnels. The old openings, writes Nitze, 

“occupy a longitudinal extent of several hundred yards, starting at Cooper's Branch. 
The strike is about N. 20° E. and the dip steeply to the northwest (nearly vertical). 
The relative positions of the old cuts show the existence of three parallel ore bodies 
or lenses, 30 and 50 feet apart.” 

The middle lens was the only one visible at the time of his visit. 
This was described as a sandy ore body 15 feet long and from half a foot 
to 3 feet wide at one place and 20 feet long and 1 foot wide at another. 
A cross-cut to the northwest from the bottom of a shaft 66 feet deep 
cut a “decomposed clay schist, interstratified with thin stringers of 
quartz.” It is noted that many specimens of the ore “show consider¬ 
able amounts of iron pyrites, and the danger is always imminent that 
this will increase below the water level." 

Three analyses of the ore are quoted: 


Partial analyses of ore from the Ferguson mine, near Bessemer City, Gaston County, N. C. 

Average Mixture 

sample from From lens from other 
surface 

4.67 


Silica (SiCb). 

Iron (Fe). 

Sulphur (S). 

Phosphorus (r’j. 

Titanium dioxide (Ti0 2 ) 
Phosphorus ratio (P:Fe) 


67.18 

.11 

.05 

.00 

.074 


From lens 
near shaft 

1 * 2.72 
57.60 
.016 
. 082 

. 142 


two lenses 

11.52 
58.20 
.012 
.071 

. 122 


No mention was made by Nitze of the openings east of the road, 
which are probably newer prospect pits in small lenses. The distri¬ 
bution of the deposits indicates the presence of a mineralized belt of 
at least an eighth of a mile wide. 

Though there are no rocks exposed near the mine there are abun¬ 
dant exposures on the road near Abernethy Creek and on t he banks of 











180 MAGNETIC IRON ORES OF EAST TENN. AND AVESTERN N. C. 

the creek. Most of the ledges are of a very fissile, white, quartz-sericite 
schist and of a light-gray, sericite slate; but on the creek west of the 
crossing and on the road west from the corner south of the mine most 
of the exposures are of quartzite or quartz schists. The series is plainly 
a sedimentary series which has been thoroughly metamorphosed to 
schists. 


Fulenwider mine 

The Fulenwider mine is represented by old openings about 1% 
miles southwest of the Ferguson mine. They are on a hill on the south 
bank of Abernethy Creek about three-quarters of a mile upstream from 
the crossing south of the Ferguson mine. The only information we have 
of this mine is contained in Kerr’s report on the iron ores of the State. 
It is stated by Hanna 169 , that the ore is characteristic gray magnetite 
in a “talcose and quartzose gangue.” Hanna also notes that the ground 
is co\ r ered with the “weathered outcrop of some yet undisco\ T ered A^ein.” 

On the writer’s Ansit to the site of the mine he found a number of 
small openings and several large ones Avest of the road crossing the creek, 
and was told that there Avere several others on the east of the road. 
All the openings are now fallen in, so that nothing of interest could be 
learned from them. However, the fields in the vicinity of the pits are 
so thickly covered Avith numerous large boulders of rusty magnetite 
that it would appear possible to Avork the soil at a profit. 

In the road are exposures of a A T ery quartzose graywacke or a quartz 
schist that is cut by veins of quartz parallel to the structure that appears 
to be bedding. The quartz is vein-like and often pure. In some places 
it contains narrow streaks of a fine-grained tourmaline aggregate. In 
other places the quartz is fractured and tourmaline occurs betAveen the 
fragments. In a few places quartz cuts the tourmaline aggregates in 
little veins and forms little nests in which the quartz exhibits the comb 
structure. Apparently there were tAvo periods of quartz intrusion, 
separated by a period during which tourmaline Avas introduced. The 
introduction of the tourmaline may have begun before the deposition of 
quartz had ceased, so that the two may haA r e been introduced together 
for a short time. Later the tourmaline was introduced in larger quan¬ 
tity. It replaced the quartz that had been introduced earlier, until at 
many places the quartz has disappeared entirely and tourmaline occu¬ 
pies its place. The tourmaline layers seen on the road A^ary in width 
from a small fraction of an inch to several inches and in some places 
gradations can be traced from tourmaline to quartz in the same layer, 
the tourmaline becoming less and less abundant on the strike until it 
disappears entirely. In a feAv places the tourmaline layers are SAvollen 

189 Kerr, W. C., and Hanna, Geo. B., Ores of North Carolina: Geol. of North Carolina 
vol. 2, pp. 161-162, 1888. 




MINES AND PROSPECTS IN SILICEOUS MAGNETITES 


181 


to a toot or more in width, and the contacts cut across layers of schist 
and quartz. 

Although there is no evidence that magnetite accompanied the 
tourmaline, nevertheless the presence of this mineral in such large 
quantity near the ore and in the same kind of rock as the latter, suggests 
that they may be related genetically. There are no exposures of the 
magnetite near the pits, but the boulders of ore strewn over the ground 
look very much like the rock exposed in the road. There is probably 
no doubt of the magmatic origin of the tourmaline and some of the vein 
quartz associated with it. If the magnetite is genetically related to 
the tourmaline it, too, must be of magmatic origin—probably the result 
of hydrothermal processes. 


Yellow Ridge mine 

The most southerly mine on the belt, known as the Yellov r Ridge 
mine, was situated on the west slope of the south end of Yellow Ridge, 
about 1 mile northwest of the “Pinnacle.” There are many openings 
still discernible on the southwest slope of the ridge and in the fields at 
its base. Some are large open pits full of water, others are old shafts 
and others are small pits. No rocks were seen on the old dumps but the 
fields around the holes are strewn with fragments of quartz and sandy 
quartzite. 

The ore found in a small stockpile is a fine-grained, porous, sandy 
magnetite containing talc or some other fibrous mineral that produces 
a crude schistosity. Much of it contains also some pyrite. A better 
quality of ore is composed of grains and crystals of magnetite embedded 
in hematite. Both types of ore resemble schists that had been impreg¬ 
nated with magnetite crystals. In the hematitic variety the schists 
remnants seem to have been replaced by hematite. 

According to Willis 170 there w r ere two groups of pits and trenches 
on the ridge about a quarter of a mile apart. At the northern workings 
the ore deposit was reported to be from 6 to 10 feet thick at a depth 
of 30 feet. A sample found near the old shaft contained 59.24 per cent 
of iron and .03 per cent, of phosphorus. 

The southern workings are more extensive. Two deposits in talc 
schists w r ere worked to a depth of 120 feet. The westernmost deposit 
contained 2 layers of ore, one 20 and the other 10 feet wide, separated 
by a thin layer of talc schist like that in which the deposit w as embedded. 
The thicker layer, which w r as the one to the w r est, contained seams of 
pyrite. The other w-as free from pyrite. The easternmost deposit 
was found only in one pit, southeast of the pits showing the double 
deposit. This was only 6 feet wide, but consisted of good ore free from 


170 10th Census U. S., vol. 15, pp. 318-319. 



182 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

pyrite. Willis regards this as a narrow part of the good ore layers on 
the east side of the pyritiferous layer farther north. Since, however, 
the pit in which it was found is 90 feet east of the strike of the good ore 
in the northern pit, it is more probably a distinct layer which is east 
of the easternmost layer to the north. The ores are interlayered with 
talcose schists which are probably interstratified with quartzite, as 
fragments of sandy quartzite are strewn over the surface near the pits. 

Two analyses of the ore from the southern openings are given by 
Willis and several others are added by Nitze 171 . The analyses quoted 
by Willis are: 

Partial analyses of ore from Yelloiv Ridge mine, Gaston County, N. C\ 



Iron 

Sulphur 

Phosphorus 

Phosphor us 
ratio 


(Fe) 

(S) 

(P) 

(P:Fe) 

Sample from pile of pyritiferous ore. . . 

57.64 

.441 

.009 

.016 

Sample from pieces of pure ore. 

57.43 

. 101 

.010 

.017 

In an anlysis of the same ore 

Hanna 172 

records 0.80 

per cent of MnO 


No ores have been discovered southeast of the Yellow Ridge de¬ 
posit on its strike. If the belt continues farther, it is so far from the 
lines of transportation that no serious explorations have been made 
in it. 


171 Op. cit., p. 107. 

172 Iverr, W. C., and Hanna. G. B., Op. cit., p. 162. 





CHAPTER IX. 


MARBLE MAGNETITES 

GENERAL CHARACTER 

The marble-magnetite ore differs from the siliceous magnetite ores 
in that it is an aggregate of magnetite and carbonates and not of mag¬ 
netite and silicates. Moreover, the ore does not occur in veins, but 
possesses more nearly the characters of a disseminated deposit. (Plate 
XXI.) At the only places where it has been seen it consists of small 
grains and small lenses of magnetite scattered rather irregularly through 
a moderately coarse-grained white marble. It occurs at two localities 
in Ashe County, N. C., and possibly at one in Carter County, Tennessee. 

ASHE MINING COMPANY’S MINE 

So far as known the deposit at Lansing, in Ashe County, now (1920) 
being operated by Mr. G. W. Cooke is the only one of its type in the 
district 173 . The mine is on the Virginia-Carolina Railroad, alongside 
Horse Creek, about 1J4 miles southeast of Lansing Station. The mineral 
rights are owned by Mr. U. Ballou. 

Pratt 174 refers to the locality under the name of the Waughbank 
property as follows: 

“About 100 yards from the creek a tunnel was run by the Penna. Steel Co. The 
tunnel has a direction of N. 40° E., and at a distance of 100 feet a crosscut was made 
extending 46 feet S. 40° W. 

“This crosscut showed ore for its whole distance, making the width of the ore 
deposit over 30 feet. This ore is composed of coarse, granular magnetite in a matrix 
composed of micaceous material and manganese oxide/' 

The vein was estimated by Pratt to be 70 per cent. ore. Analyses 
of a fair sample of the vein and of a selected sample of the magnetite 
gave: 

Partial analyses of ore from Waughbank property, Lansing, Ashe County, N. C. 

Fair Selected 

sample sample 

Iron (Fe). 46.25 67.25 

Manganese (Mn). 4.34 1.68 

Sulphur (S). • 027 . 

Phosphorus (P). .026 . 

Titanium (Ti) . Tr. . 

This is evidently the same deposit as that described by Nitze 175 
as “Ballou’s Horse Creek ore bank.” At the time Nitze wrote the 

173 See also - Bayley, W. S., A magnetite-marble ore at Lansing, N. C.: Jour. Elisha 
Mitchell Sci. Soc., vol. 37, No. 3 and 4, p. 138 1922 . . inio XT ^ 

174 Pratt, J. H., The mining industry in North Carolina during 1911 and 1912: is. C. 
Geol. and Econ. Survey Econ. Paper No. 34, p. 68, 1914. 

175 Op. cit., p. 156. 












184 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

opening was in the “shape of an undercut in the side of the hill into 
which it extends perhaps 50 feet as a slope." The seam which dips 
northeast is at least 6 feet wide, the lower two feet being the harder. 
Nitze’s analyses correspond closely with those furnished by Pratt. 
They are as follows: 

Nitze’s analyses of ore from Waughbank property, Lansing, Ashe County, N. C. 

1 2 


Silica (Si0 2 ). 

_ 1.96 

4 

.58 

Iron (Fe). 

_ 62.48 

54 

.02 

Manganese (Mn). 

_ 3.66 

6 

.85 

Sulphur (S). 

_ .072 


007 

Phosphorus (P). 

... .019 


Oil 

Phosphorus ratio (P:Fe). 

_ .030 


017 


Mr. Cooke declares that the “Waughbank" property was the same 
as that he is now working, but that the original opening which dates 
back as early as 1828 was on top of the hill about 50 feet above the 
present tunnel. The tunnel of the Penna. Steel Co. was opened about 
15 years ago into the lower portion of the Waughbank deposit. It is 
parallel to the present tunnel and about 40 feet above it. It is frequently 
referred to as the upper level. At its end, at the bottom of the Waugh¬ 
bank pit, a little ore in marble was encountered, but most of the ore 
developed by it was of the siliceous type. The relations of the two 
tunnels to one another and the mutual relationships of the siliceous ore 
and that now being worked are shown in the sketch. Figure 20. 

Chemical and mineralogical composition of ore 

The ore of the deposit now being worked is essentially a coarsely 
granular intermixture of carbonates and magnetite. Here and there 
are grains of quartz but they are rare. The carbonates are in large 
grains with perfect cleavage constituting a white marble. A partial 
analysis of this marble, which was made by Mr. J. G. Fairchild, in the 
U. S. Geol. Survey laboratory gave: 

Partial analysis of marble from Ashe Mining Co.’s mine, Lansing, Ashe County, N. C. 

Carbon dioxide (C0 2 ). 34.28 Magnesia (MgO). 9.17 

Lime (CaO). 26.32 Manganese oxide (MnO),.Some 

This is equivalent to a mixture of one part MgC0 3 to two parts 
CaC0 3 with an excess of 3.50 per cent. C0 3 , that is believed to be com¬ 
bined with manganese, which was not determined. If this supposition 
is correct the specimen analyzed contained about 9 per cent, of MnC0 3 
and the marble consists of 62 per cent. CaC0 3 , 26 per cent of MgC0 3 
and 12 per cent, of MnC0 3 . 

The magnetite is in irregular slightly elongated grains scattered 
through the marble, producing an ill defined schistosity, which is em¬ 
phasized by the occasional accumulation of the magnetite grains in 
lenses with their long axes parallel to the obscure schistosity of the 
matrix of marble and magnetite in which they lie. (Plate XXI, B.) 












PLATE XXI. 




Polished surfaces of the marble-magnetite ore from Ashe Mining Co.’s mine, 
Lansing, Ashe County, N. C. (Natural size.) 

(A) Ordinary ore. ( B ) Contact of ore lens with marble. 



186 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

In a few places the rock is markedly schistose. This is brought about 
by the elongation of the magnetite grains in a common direction and by 
the occurrence of many of them in plates, suggesting the plates of hema¬ 
tite in specular ores. Many of the elongate grains are sheared along 
cleavage planes and drawn out into lines or rows of sharp edged particles. 
The carbonate grains associated with the magnetite show no similar 
elongation but the schistosity is often accentuated by the presence of 
calcite veins or layers running in the same direction as the lines of mag¬ 



netite plates. Evidently the carbonates have been entirely recrystal¬ 
lized since the rock's deformation. Here and there through the rock are 
embedded small garnets, which in many cases are altered so as to give 
rise to light brown stains. 

Some of the marble-magnetite is too poor in iron to be regarded as 
an ore, but by rejecting this the balance passes as an ore which though 
possibly ’ow grade with respect to iron is available to the furnace be¬ 
cause practically all the material that is not iron is marble, which serves 
as a flux. 



















MARBLE MAGNETITES 


187 


In thin section a typical lean ore shows coarse grained aggregates 
of two colorless carbonates, of which one is caleite and the other probably 
dolomite, a few plates of phlogopite and large irregular masses of mag¬ 
netite. The mica is in streaks of plates extending in nearly straight 
lines through the section with the individual plates lying between ad¬ 
joining carbonate grains and more frequently than otherwise near the 
magnetite. This mineral is often in large areas with very ragged boun¬ 
daries, the salients of which project considerable distances between the 
grains of carbonate, or between their contiguous twinning lamellae. 
Occasionally a smaller grain appears to be enclosed in grains of what is 
regarded as dolomite, and in other instances the larger masses appear to 
enclose small grains of the carbonate. From the fact that the car¬ 
bonate inclusions polarize uniformly with the large grains surrounding 
the magnetite it is thought that the apparent inclusions are merely por¬ 
tions of projections that extend into the embayments of the magnetite 
and that their appearance as inclusions surrounded by magnetite is 
due to the fact that the section was cut through the boundary between 
magnetite and carbonate. The richer ore differs from the poorer ore 
mainly in the larger sizes of the distributed magnetite grains and espec¬ 
ially in the much greater sizes of the magnetite lenses. Some of the 
latter are a foot or more in length and 5 or 6 inches in diameter. 

As elected sample of the richest ore freed from adhering limestone 
was analyzed by J. G. Fairchild of the U. S. Geological Survey, with 
the result shown below: 

Chemical Composition of Magnetite from the Ashe Mining Company's mine, Lansing, N. C 


Silica. 

.(Si0 2 ) 

2 

.33 

Alumina. 

.(Aid), 

2 

.38 

Ferric oxide. 

.(Fe 2 0 3 ) 

60 

.42 

Chromic oxide . 

.(Cr 2 0 3 ) 


.00 

Ferrous oxide. 

.(FeO) 

24 

.80 

Manganese oxide. 

.(MnO) 

3 

.01 

Magnesia. 

.(MgC)j 

3 

.37 

Lime. 

.(CaO) 

1 

. 14 

Soda. 

.(Na 2 0) 


.26 

Potash. 

.(K 2 0) 


Tr. 

Titanium dioxide. 

.(TiO,) 


Tr. 

Carbon dioxide. 

.(C0 2 ) 

1 

.97 

Phosphorus pentoxide.... 

.(P«0.) 


Tr. 

Sulphur trioxide. 

.(S0 3 ) 


.11 

Water above 110°. 

.(H,0+) 


.83 

Water below 110°. 

.(H 2 0—) 


.04 

Sulphur. 

.(8) 


.00 

Vanadium pentoxide. 

.(V 2 0 5 ) 


.00 

Baryta. 

.(BaO) 


. 00 

Strontia. 

.(SrO) 


.00 

Fluorine. 

.(F) 


.00 


. 

100 

.66 
























188 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

This is the analysis of a very pure magnetic ore. A calculation 
indicates the presence in it of the following components: 

Approximate mineral composition of Lansing magnetite 


Magnetite. 87.5 

Carbonates. 3.5 

Albite. 2.1 

Pyrite. • 1 

Silicates. 6.8 


100.0 

The magnetite is remarkably pure. Since the total of all the car¬ 
bon-dioxide in the analysis is sufficient to allow o; only about 0.4 per 
cent of MnO to combine in the form of manganese carbonate the re¬ 
mainder of the manganese must be in the magnetite. The ore is not¬ 
ably free from titanium. In the absence of this element and the pre¬ 
sence of manganese this ore closely resembles the magnetite 176 in the 
Franklin limestone in New Jersey. 

The percentage of iron indicated by the analysis is 61.58 and of 
Mn 2.33 but this analysis is of a selected sample from which material 
other than magnetite has been removed as thoroughly as possible by 
careful hand-picking. The ore furnished to the Cranberry Furance is 
shipped as taken from the mine, without crushing and careful selection. 
This, therefore, is much lower in iron, and indeed considerably lower 
than the minimum limit for ordinary magnetic ore; but because of its 
extremely low phosphorus and high calcium is acceptable. 

Analyses of many carload lots made at the Cranberry Furnace at 
Johnson City showed limits of 36.43—52.93 for iron and 0.0094—0.0114 
for phosphorus. A series of analyses 177 of 7 cars received during the 
fall of 1919 gave: 

Iron. 40.65 42.76 46.46 39.07 40.65 35.11 38.54 

Phosphorus.0062 .0052 .0052 .0052 .0042 .0062 .0057 

One analysis 178 of a car of ore very low in iron yielded iron, 30.52 
per cent; phosphorus, 0.0052 per cent, and lime 17.84 per cent. This 
is equivalent to 42.14 per cent of magnetite and 31.86 per cent of 
calcite (CaC0 3 ), or a total of 76 per cent. There was no record made 
of the other 24 per cent. 

Association of minerals in the ore-mass 

The greater portion of the ore, as has been related, is mainly a 
coarsely crystalline marble containing grains and lenses of magnetite. 
In many places, however, it contains vein-like layers of a bright-green, 
fine-grained granular actinolite, which, where shearing occurs, is changed 

178 Bayley, W. S., Iron mines and mining in New Jersey: Geol. Survey of N. J., Final 
Report Series of the State Geologist, vol. 7, p. Ill, 1910. 

l77 Furnished by Pres. F. P. Howe, Cranberry Furnace Co., Johnson City, Tenn. 

178 Made by Cranberry Furnace Co. Furnished by Mr. Cooke. 











MARBLE MAGNETITES 


189 


to a mass of bright-green actinolite fibers. Often magnetite is present 
in the granular aggregate, and this is noticeably more abundant near 
the contact of the green layer with the marble. It not infrequently 
happens that there are distinct lenses of magnetite at the contacts of 
the two rocks even though magnetite is not present elsewhere in asso¬ 
ciation with the green rock, and occasionally a continuous thin layer 
of magnetite separates the two for considerable distances. The actino¬ 
lite layer passes into the marble by a very gradual transition—the actino¬ 
lite becoming less and less abundant until it forms a very small portion 
of the mass. 

The actinolite layer is in reality complex. It consists of an aggre¬ 
gate of thin layers and flat lenses made up mainly of equidimensional 
prisms of actinolite that are pleochroic in very light yellowish-green 
and emerald-green tints. These alternate with equally thin layers of 
carbonates. The maximum extinction of the actinolite is about 20°. 
Among the actinolite prisms are scattered a few large grains of calcite, 
a very few large plates of a colorless mica, perhaps phlogopite, and large 
irregular masses of magnetite. The actinolite appears to occur in 
streaks between bands of calcite, as though in crush zones, and the in¬ 
dividual prisms have a general parallel elongation in the direction of 
the streaks. Many of the magnetite masses are also crossed by tiny 
cracks filled with calcite. 

Envelopes of actinolite surround many of the lenses of magnetite 
in the marble and veins of actinolite cut through them. The magnetite 
in such lenses is cleaved and the lenses are granular masses composed 
of elongate grains of the magnetite. The long dimensions of the magne¬ 
tite and the long directions of the actinolite fibers in the veins are pa¬ 
rallel, but there is no definite relation between the elongation of the 
fibers and the direction of the veins. Their fibrosity may be parallel 
to the walls of the veins, perpendicular thereto or inclined to them at 
any angle. Whatever the direction of the fibers with respect to the 
veins, they are all parallel within the mass of a single hand-specimen. 

In other specimens veins of actinolite traverse masses of magnetite 
and marble, and sporadic garnets appear in the mass. 

The suggestion furnished by the sections is that a mass of marble 
and magnetite became shattered as the result of movements, and the 
cracks between the fragments were filled with actinolite formed by 
metamorjdiosing processes during the course of this movement. At the 
same time some of the magnetite was cracked and some calcite which 
was undergoing recrystallization at the time was forced into the frac¬ 
tures. In some places calcite veinlets were formed and in other places 
actinolite veins resulted, and because the development of the actinolite 
took place under differential pressure, the fibrosity of this is every- 


190 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

where parallel. It is probable that the lenses of magnetite are also 
secondary forms, though the magnetite itself was present previous to 
the deformation. 

There was evidently motion in the rock-mass also after the actino- 
lite was formed and after the magnetite was shattered, since there are 
present in it the slickensides coated with acicular actinolite, in many 
places to a thickness of half an inch or more. In these places there are 
usually streaks of magnetite next to the actinolite, and in the magnetite 
are frequently small streaks of pyrite. That these various deformations 
produced little visible effect upon the structure of the carbonates is 
probably due to the fact that most of these minerals recrystallized after 
the action of the forces producing the deformation had ceased. 

Here and there through the ore there is also considerable dark 
hornblende. It occurs in large quantity in some fragments on the 
dump. It apparently is in fairly large dikes composed of intermingled 
hornblende, magnetite and, in many cases, garnet. Where the dikes 
are a foot or more wide their interiors consist of a coarse aggregate of 
black hornblende and magnetite free from garnet. In the smaller dikes, 
on the other hand, the hornblende in some places encloses small lenses 
of carbonates and in others lenses in which the carbonates have been 
nearly completely changed to pink garnet. In some dikes garnet and 
hornblende are in equal quantities. In many places the marble in 
contact with the hornblende is banded and in other places it contains 
lenses of magnetite. In contact with the hornblende-garnet is a narrow 
layer of fine-grained hornblende, carbonates and pyrite with the latter 
usually in very thin seams parallel to the boundary. Beyond this are 
bands of carbonates and magnetite. The banding is thus the result of 
consecutive layers of coarse, black hornblende, aggregates of black 
hornblende and red garnet, aggregates of fine-grained dark and light 
hornblende, thin seams of pyrite and of carbonates, streaks of magnetite 
and finally layers of carbonates and black mica. There is no common 
elongation of the carbonate grains in the marble, but the rock in the 
neighborhood of the dikes has a distinct schistosity due to the parallel 
arrangement of the layers. 

In many places near the borders of the ore-mass and occasionally 
within its mass are also irregular aggregates of red garnet, black horn¬ 
blende, magnetite and carbonates in which the garnet is predominant. 
The hornblende on the whole looks as though it were intrusive and the 
garnet as though a contact product between hornblende and the car¬ 
bonates. These aggregates are traversed by little veins of white cal- 
cite and colorless quartz and contain here and there nests of these min¬ 
erals, which are unquestionably secondary. 

Pyrite is not common anywhere in the ore. At a few places it 
occurs as thin layers between the layers of granular, light-green horn- 


MARBLE MAGNETITES 


191 


blende and the marble and in a few places scattered through the mag¬ 
netite-marble rock in large masses that enclose particles of the other 
components. Some of the particles are plainly large skeleton cubes, 
poikilitically developed. In other words, they possess the sieve struc¬ 
ture which is characteristic of minerals formed after the rock in which 
they are found. In some cases the pyrite apparently replaces calcite 
and in other cases magnetite. It is believed that it was not a part of 
the original rock but was subsequently introduced. 


Pegmatite veins in the ore 

In places epidotized pegmatites are associated with hornblende 
masses. Where they cut the country gneiss in the vicinity of the mine 
large garnets occur near their contacts. Where they are associated 
with the hornblende masses in the ore the pegmatites are fine-grained 
and aplitic and there are few garnets at their contacts. This mineral 
is confined mainly to the contacts between the hornblende and the 
marble. 

In thin section the fine-grained veins are seen to be badly crushed 
pegmatites. Their quartz areas are aggregates of small quartz grains 
and their former feldspar grains are now aggregates of small, very light- 
yellow epidote grains. There are, however, no sharp boundaries be¬ 
tween the feldspar and the quartz areas. These have been obliterated 
by the crushing. The quartz areas near their borders are full of epidote 
grains and the epidote areas contain nests of quartz grains and, further 
within their interiors, individual grains of quartz. Moreover there are 
little veins of epidote in the quartz, and vein-like masses of quartz in 
the epidote aggregates. 

The contact of the veins and the hornblende mass is also far from 
sharp. At some places there is a streak of small pink garnets separating 
the two, but for most of the distance the epidote aggregate penetrates 
the hornblende mass and hornblende grains are embedded in the epidote. 
The hornblende mass consists mainly of large crystalloids of hornblende 
—yellow-green—with large nuclei composed mainly of partly amplii- 
bolized light-yellowish augite. Often the partially altered pyroxene 
comprises three-quarters of the area of the grain, and around it is a 
zone of compact green-yellow hornblende with sharp projections ex¬ 
tending from the more compact portion. Extinctions of 24° against 
the cleavage in the surrounding zone and 45 in the nucleus are 
characteristic. In the spaces between neighboring pieces of hornblende 
are small nests of quartz and calcite and often in pieces of the amphibole 
that are not so compact are enclosures of quartz and many more of 
calcite. The areas between the large amphibole grains are commonly 
filled with quartz and calcite grains and spicules of green hornblende. 


102 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


These fine-grained veins are believed to be small veins of pegmatite 
that have been completely granulitized, and thus have lost all traces 
of their granular structure. It is significant that few garnets occur 
at their contacts with the hornblende through which they pass, but that, 
on the other hand, garnets are at many places along contacts of the 
hornblende masses with the marble surrounding them. Where pegma¬ 
tites cut the country gneiss in the vicinity of the mine large garnets 
occur in the gneisses near the contact. It may be fair to assume there¬ 
fore that the hornblende masses are a part of the pegmatite, since upon 
this assumption the presence of garnets between them and the marble 
is easily explained as due to contact action. Moreover, the hornblende 
is an altered augite—mid in the Cranberry area the pegmatites associated 
with the ore were originally an augitic variety. 

The relations of the pegmatite, hornblende and limestone, together 
with the presence of garnets and of streaks of magnetite near the bor¬ 
ders of the hornblende are suggestive of contact action. In the old 
Waughbank mine the ore w T as of the same character as that in the Cran¬ 
berry mine. If the views of Mr. Cooke are correct the Waughbank ore 
gradually passed into the limestone ore now characterizing the Lansing 
mine. There is very little definite pegmatite in the Lansing mine unless 
it is represented by the hornblende streaks and the fine-grained veins 
described above, but there is pegmatite in abundance in the old Waugh- 
bank openings. The hornblende streaks in the Lansing mine may 
very well have been very basic phases of augitic pegmatite, which 
added iron and perhaps silica to the limestone and brought about con¬ 
tact action by which garnets, phologopite and actinolite were produced. 

The ore-body 

The ore-body of the Lansing mine is reached by a tunnel running 
into the base of the hill 150 feet in a direction N. 40° E., just above the 
level of Horse Creek. It is in the foot-wall which is a light-gray mica 
gneiss, very much like the country rock described below' but much 
more thoroughly crushed. Most of the slide consists of a quartz- 
feldspar mosaic. In this are large remnants of plagioclase, crushed 
grains of quartz, and many small brownish green flakes of biotite. The 
plagioclase remnants contain more epidote than is found in the feldspar 
of the gneiss further from the contact, and there is present in it a great 
deal more calcite. Between this gneiss and the ore-body is a thin layer 
of gray mica schist, which may readily be a result of shearing of the 
gneisses along the contact. Immediately above the ore is another thin 
sheet of a similar schist and above this a light-gray, fine-grained gneiss 
that may be a part of the Cranberry granite series. 

The country rock is a coarse, gray, banded gneiss that looks very 
much like a squeezed porphyritic granite. It consists of brown-green 


MARBLE MAGNETITES 


193 


biotite plates and large pieces of crushed plagioclase in a mosaic of 
of quartz, plagioclase and orthoclase, in which are also tiny wisps of 
biotite, small grains of epidote and nests of calcite. This is interlayered 
with light-colored gneiss which was originally an augitic syenite. It 
now consists of large anhedrons of a microperthitic feldspar, large light- 
green masses of amphibole, containing here and there nuclei of pyroxene, 
and surrounded by a border of tiny epidote crystals lying in all azimuths. 
There are also present a small quantity of brown biotite and a few large 
grains of quartz. The feldspars are crushed around their edges into a 
fine-grained mass which now consists of quartz, epidote and pale-green 
amphibole. These gneisses are intersected by veins of pegmatite that 
is almost devoid of dark components, and on the borders of which are 
large garnets. In many places the feldspar of the pegmatites is partially 
changed to epidote as at Cranberry. In a cut on the railroad layers 
of hornblende schist are in the gneisses, and along these shearing took 
place with the production of actinolite-asbestus. 

The ore-body is very irregular in shape and is sharply marked off 
from the country rock by the layers of schist below and above. In 
general it strikes about N. 35° E. as the tunnel which runs N. 40° E. 
in the foot wall strikes the ore at its end. Its dip is about 40° SE. In 
a portion of its course the dip and strike are regular, indicating a width 
of only 4 feet and in some places the ore is cut out entirely by what ap¬ 
pear to be great fragments of the country rock or by small faults. Near 
the present end of the tunnel the ore-body is chimney-like. It was 
encountered in an old hole on the surface above the tunnel and was 
followed downward in a small steeply pitching shoot into the present 
ore-body where it expands into a sheet with the dip and strike of the 
surrounding gneisses. At the foot-wall is a narrow seam of calcite that 
appears to be secondary as it sends veinlets into the contiguous ore and 
gneisses. 

In mass the ore-bodv appears distinctly schistose. On its borders 
are selvages of garnet and hornblende, several feet thick, but within 
these the ore is fairly uniform in character, varying only in the propor¬ 
tions of magnetite and carbonates present. Here and there near its 
edges are pockets of loose magnetite, especially near the foot-wall, 
where the sparse calcitic cement in lenses of granular magnetite may have 
been dissolved by persolating water. The pyrite that has already been 
referred to is confined almost exclusively to the borders of the ore-body 
and to the vicinity of little veins of hornblende cutting through it. It 
is apparently most abundant where shearing has taken place. From 
the main mass of the ore-body the mineral is entirely absent, so that it 
has no bad effect upon the ore. Through the ore are small vein-like 
masses of coarse black hornblende or of hornblende and magnetite all 
running parallel to the schistosity of the ore, which is parallel to the 


194 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

general strike of the ore-body, thus accentuating the structure. In 
some places there are also present in the marble streaks of magnetite 
that suggest very strongly little dikes. These are rarely more than \}/2 
inches wide. Their walls are nowhere sharp, but on the contrary on 
their margins the magnetite layers pass into the marble by gradations, 
the carbonate grains becoming more and more abundant toward the 
marble side of the contact until finally the rock becomes essentially a 
nearly pure marble. 

The thin section shows the magnetite streaks to be aggregates of 
calcite, actinolite and magnetite, with the last named of course pre¬ 
dominating. The marble contains considerable light-green tremolite 
or actinolite in plates and little radiate bunches. These usually form 
bands that stretch across the section in striaght courses. The plates 
and bunches are between the carbonate grains, and they lie irregularly 
within the streaks. There is possibly a slight tendency to a parrallel 
arrangement, but it is scarcely noticeable. There is no observable de¬ 
finite disposition of the actinolite with respect to the magnetite that is 
present in the section. This mineral is in irregular grains. It often 
appears to enclose calcite grains. Narrow streaks extend between ad¬ 
jacent carbonate grains and completely embrace them, as though the 
magnetite had entered the rock and penetrated its substance. 

OTHER MARBLE-MAGNETITE ORES 
Pit on Dr. Jones’s property 

The only other point at which the conditions appear to be similar 
to those at the Ashe Mining Company’s mine is a few yards north of 
Dr. Jones's residence, about a third of a mile northeast of the railroad 
station at Lansing and three-quarters of a mile N. 20° E. of the Ashe 
Mining Company’s mine. (See Figure 15.) Here a pit was started at 
a place where there was much magnetite in the soil. At the depth of 
25 feet a piece of limestone was encountered in the midst of the gneisses, 
with manganese ore on opposite sides. The hole is now filled, but on 
the old dump, which has almost entirely disappeared, a fragment of 
actinolitic rock was found that is unquestionably a metamorphosed 
limestone consisting of calcite, actinolite and tremolite. 

Red Rock mine 

Since returning from the field the study of the specimens collected 
suggests that possibly the Red Rock mine about 1^ miles southeast of 
Shell Creek in Carter County, Tennessee, and 1 mile from the North 
Carolina State line, is another instance of a deposit of ore in marble. 

Information as to the character of the Red Rock ores is furnished 
only by the fragments on the dumps. Here are to be found pieces of 


MARBLE MAGNETITES 


195 


ore cut by epidote veins, fragments consisting of granular aggregates of 
black h ornblende, epidote and magnetite, and others composed of 
garnet, magnetite, hornblende, and calcite. It is the abundance of 
garnet in this ore that suggested the name Red Rock for the deposit. 
(See also page 122.) 

ORIGIN 

If the theory with regard to the origin of the Cranberry ore is cor¬ 
rect, and the magnetite at Cranberry is due to deposition from ascend¬ 
ing hot liquids and gases brought upward by augitic pegmatite, it 
seems probable that the marble ores are likewise the result of pegmatitic 
solutions. Old limestones were metamorphosed by solutions producing 
garnet and actinolite from the constituents of the limestone and adding 
components from which were made dark hornblende and magnetite. 
The distribution of the components of the ore is such as would occur 
if they were produced by hydrothermal contact action, emanating from 
dikes of pegmatite. No distinct dikes of pegmatite are to be seen cut¬ 
ting the marble ores, but they are believed to be represented by the small 
veins of epidote that traverse it, by the aggregates of epidote and mag¬ 
netite and those of hornblende and magnetite that appear as streaks in 
it and by the lenses of dark hornblende that are embedded in it here and 
there. The epidote is believed to represent the feldspar of the pegma¬ 
tite. All gradations between pegmatite in which the feldspar is only 
slightly epidotized and that in which all the feldspar has been replaced 
by epidote are common in the Cranberry area. At Lansing very little 
of the pegmatite magma reached the position of that portion of the ore- 
body now being worked, but the gases and liquids travelled along the 
contacts between the limestone and the gneiss, penetrated the limestone 
near the contacts and caused the deposition of garnet and magnetite 
which has been described as forming a selvage on the borders of the ore 
body. The marble was a part of the schist series at the time the peg¬ 
matite was intruded. 

The fact that marble-magnetite ores are so rare is due to the 
fact that the limestone beds themselves are rare. The best known 
occurrence is in a cut on the Carolina, Clinchfield & Ohio Railway at 
Intermont which is about 4 miles south of Toecane. The limestone 
is a coarse white marble described by Keith 179 as consisting of 55 per cent 
of CaC0 3 and 45 per cent MgC0 3 . It is associated with gneisses and 
pegmatite. It is mapped as being in the Carolina gneiss—a series of 
micaceous and garnetiferous schists and micaceous, garnetiferous and 
cyanitic gneisses which are believed to be the oldest rocks in the region. 

A sketch of the exposure is reproduced in Figure 21. This shows 
the marble to be in fragments separated by gneiss and pegmatite. At 


i79U. S. Geol. Survey Geol. Atlas, Mount Mitchell folio (No. 124), pp. 2-3, 1905. 




196 MAGNETIC IKON ORES OF EAST TENN. AND WESTERN N. C. 

the south end of the section near its bottom the marble is in contact 
with the pegmatite and with gneiss. For three-quarters of an inch 
from the gneiss the marble is bordered by a light-gray zone in which 
are many plates of a light-yellow mica resembling phlogopite, a few" 
plates of biotite and an occasional garnet. Immediately at the contact 
is a layer of light-brown phlogopite. 



Figure 21. Sketch of marble exposures at Intermont, near Toecane, on the Carolina, 
Clinchfield & Ohio Railway, Mitchell County, North Carolina. 

At the contact with the pegmatite the contact zone is about lj/^ 
inches wfide, and is composed of tw r o layers, the inner one of which is 
characterized by the presence of plates of tremolite and more scanty 
plates of wollastonite scattered through the marble, but mainly in such 
a way as to constitute bands running parallel to the contact. The tremo¬ 
lite is generally fresh and colorless but the w r ollastonite is traversed by 
many cracks in which have been deposited fibers of a light-green mica¬ 
ceous mineral, with a slight pleochroism in greenish and yellowish tones. 
Some of the tremolite flakes are tinged with green. These are very 
slightly pleochroic thus approaching actinolite in character. The outer 
zone consists exclusively of a light-gray platy tremolite arranged with 
its long directions perpendicular to the contact. The tremolite strongly 
resembles the mineral at the Lansing mine that has been called actino¬ 
lite. Whether the two minerals are actually the same or are different 
is of little importance. Their presence indicates that the pegmatite 
added material to the limestone in both cases. The irregular distribu¬ 
tion of the marble, parts being almost competely surrounded by silicate 
rocks, suggests an explanation of the irregular distribution of the ore 
at Lansing. The limestone bed was broken into fragments as at the 
occurrence on the railroad and the marble ore naturally possesses a 
similar distribution. 

PRODUCTION AND RESERVES 

The mine at Lansing has been operating for only a short time. 
About 500 carloads of ore had been shipped to August, 1919. At present 










MARBLE MAGNETITES 


197 


there is an exposed face of ore measuring 10 feet high and 30 feet along 
the strike of the vein, which here is apparently a sheet parallel to the 
foliation of the country rocks. There are no explorations to show 
whether the sheet is continuous along its strike or dip and consequently 
there is no means of estimating the magnitude of the reserve. Although 
the vein looks more regular at its present depth than it was nearer the 
surface, nevertheless there is no certainty that it will not suddenly 
become broken and irregular. 

Because of the irregular manner of distribution of the marble in 
the schists it is impossible to estimate with any probability of correctness 
the quantity of ore that may be expected. It may extend beyond the 
present workings for a long distance, or, if the marble is shattered as it is 
near Toecane, it may terminate within a few feet of them. In either 
event it is probable that the marble ore may be replaced by siliceous 
ore such as was found in the old Waughbank opening above the present 
mine, in which case it may be valuable or worthless, depending upon 
the width of the vein. The marble ore is merchantable even when its 
iron content is as low as 35 per cent. The siliceous ore must carry 
much more iron before it will be accepted at the furnace, and most of 
it therefore must be concentrated. 


CHAPTER X. 


TITANIFEROUS MAGNETITES 

CHARACTERIZATION 

The titaniferous magnetites are those in which the content of 
titanium is so high as to give trouble in the modern blast-furnace. Nearly 
all of the magnetic ores in East Tennessee and western North Carolina 
contain more or less titanium, but there is a rather definite separation 
of them into two groups, in one of which are ores containing one per 
cent, or less of Ti0 2 and in the other ores containing 4 per cent or more 
of this oxide. Moreover nearly all the richly titaniferous ores are known 
to contain small quantities of chromium. (See page 203.) 

At the present time it is difficult to learn much about the occurrence 
and associations of the titaniferous magnetites as their deposits have 
been abandoned for such a long time that the openings upon them have 
become completely filled with debris. It is necessary, therefore, as in 
case of the more common magnetites, to depend largely upon the de¬ 
scriptions given by those who visited the openings while exploratory 
work was being done, and to supplement these descriptions by the ex¬ 
amination of thin sections of pieces of rock and ore found on dump 
heaps in order to gain any information as to the occurrence and origin 
of the ores. 

DISTRIBUTION 

In general, the titaniferous magnetites, like the more common 
magnetites, occur in belts or zones in crystalline rocks in the mountain 
district and in the Piedmont Plateau. (See Figures 13, 22 and 23.) 
The country rocks in the mountain district are believed to be of Archean 
age 180 and those in the Piedmont Plateau of either Archean or Algonkian 
age. 181 

The ore-bodies are in the form of distinct veins, or dikes, cutting 
through the schistose rocks in the direction of their schistosity. The 
e s \ ary in widtli from several inches to 20 feet. They may extend 
along their strikes for from 25 or 30 feet to 300 or 400 feet or more. 
They may consist of a single sheet of the ore-mineral or of several sheets, 
separated by chloritic or serpentinous material. In the mountain dis¬ 
trict the deposits appear to be isolated, even those on the same belt 
being separated from one another by pinches of the country rocks 
In the great belts in Guilford and neighboring counties, however, the 
ore-bodies are described “as strings of lens-shaped masses, continually 
enlarging and contracting in thickness, from a few inches to 6 feet and 

180 Keith, Arthur, U. S. Geol. Survey Geol. Atlas, folios Nos. 90, 116, 124 and 151. 

181 Keith, Arthur, and Sterrett, Douglas B., U. S. Geol. Survey Bull. 660, p. 126, 1918. 




TITANIFEROUS MAGNETITES 


199 


8 feet. 18 - The deposits are irregular in position in the belt, in some 
places being in a linear series and in other places lying side by side. 
They therefore do not constitute a continuous body the full length of 
the belt, as was repeatedly stated to be the ease in the earlier descriptions 
of the occurrence. Singewald 183 declares that the ore-bodies are segre¬ 
gations within small gabbro masses that have “a linear distribution 
along the belt, and that the rock immediately associated with the ore at 
the Tuscarora mine is an olivine gabbro. 


COMPOSITION 

Most of the titaniferous ores in the area under discussion may be 
mixtures of magnetite and ilmenite as similar ores in other districts are 
said to be. Others are now mixtures of magnetite and rutile, though 
originally they may have been ilmenite. Both these types of ore are 
magnetic. The ores of the Smith and Pennington places in Ashe County 
are of this kind. (See pages 210 and 216.) Some of the ores richest in tit¬ 
anium exhibit no magnetism when subjected to the influence of an ordinary 
horseshoe magnet. In these the titanium cannot be present as rutile, 
since if this were so there would necessarily be present considerable 
quantities of magnetite and the mixture would be magnetic. A com¬ 
parison of the quantities of iron and titanium present in these varieties 
indicates that the proportions are approximately those of iron and 
titanium in pure ilmenite. 

Singewald 184 has concluded, as the result of his metallographic 
studies of the titaniferous ores of North Carolina that some are pure 
ilmenites and others intergrowths of magnetite and ilmenite. The 
study of thin sections of the titaniferous ores of North Carolina has 
shown that some of them contain large quantities of rutile. a 

Singewald 185 has called attention to the fact that Soligman, Cathrein 
and Miigge have described intergrowths of rutile in magnetite, and 
W arren 180 has pointed out that some of the analyses of titaniferous iron 
ores from well-known localities show an excess of Ti0 2 over that required 
for ilmenite. This he surmises is in the form of rutile, though positive 
evidence that this is the case is lacking. (Compare page 232.) How¬ 
ever, a few pebbles from placer concentrates on the Pacific coast showed 
intergrowths of ilmenite and rutile and in one of these there appeared to be 
a replacement of rutile by ilmenite, as the outside of the pebble was 


182 lNitze, H. B. C., Iron Ores of North Carolina: N. C. Geol. Survey Bull. No. 1, p. 62, 

1893. 

183 Singewald, Jos. T., Jr., The titaniferous iron ores in the United States: U. S. Bureau 
of Mines Bull. 64, p. 86, 1913. 

184 Singewald, J. T., Jr., The titaniferous iron ores in the United States: U. S. Bureau 
of Mines Bull. 64, pp. 80-93, 1913. 

(a) Bayley, Vv. S., The occurrence cf rutile in the titaniferous magnetites cf Western 
North Carolina and Eastern Tennessee: Econ. Geol., vol. 18, p. 382, 1923. 

185 Op. cit., pp. 24, 27. 

i86Warren, C. H., On the microstructure of certain titanic iron ores: Econ. Geology, 
vol. 13, pp. 419-446, 1918. 



200 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

almost entirely ilmenite (page 437 fc ). In the cases described by Cathrein 
and Warren the rutile was in lamellar intergrowths in which the lamellae 
were so narrow that it was difficult or impossible to identify the rutile 
with certainty. On the other hand, in a rutile-sapphirine-ilmenite at 
St. Urbain, Quebec, Warren 187 finds the ilmenite to be “thickly sprinkled 
with grains of an orange-red rutile, a smaller amount of feldspar, biotite, 
sapphirine, or their decomposition products, and spinel (page 208.). 
The rutile is in the form of crystal grains or clusters, distributed nearly 
uniformly through the ilmenite, which is in irregular grains composed 
of a lamellar intergrowth of ilmenite and hematite. In the rutile- 
nelsonite 188 in Goochland and Hanover counties in \ irginia the rutile 
may be intergrown with ilmenite, but the material is so thoroughly 
crushed that the nature of the intergrowth was not determined. 

In the few sections of the North Carolina ores that have been ex¬ 
amined microscopically the rutile is not in minute needles, nor in de¬ 
finite grains uniformly distributed through magnetite or ilmenite, but 
is for the most part in broad yellowish-brown translucent masses which 
in some places are wider than the opaque magnetite or ilmenite between 
them. (Plates XXII and XXIII.) In the Tuscarora, ore, however, 
some of it appears to be in crystals embedded in magnetite. 

The appearance in the first variety is as though the rutile had formed 
along definite planes and had gradually replaced the magnetite or il¬ 
menite on both sides 189 , until in some specimens there is now left only 
a narrow layer of the opaque mineral between neighboring layers of 
the brownish rutile. That the opaque mineral is magnetite rather than 
ilmenite is indicated by the strong magnetism of the ore. It is possible 
that the material of the ore grains was once an intergrowth of magnetite 
and ilmenite and that the present interlayering of magnetite and rutile 
is the result of some sort of metamorphism of the ilmenite. 190 Van 
Hise 191 has noted that ilmenite changes to magnetite and rutile. The 
change certainly occurs in the zone of katamorphism (i. e., near the 
surface), but there is not sufficient information on the subject to warrant 
an assertion that it does not also occur in the zone of anamorphism ( i. e ., 
at great depths.) If the rutile in the North Carolina occurrences is 
an alteration product of ilmenite it is difficult to decide whether it should 
be regarded as the result of weathering or of conditions that prevailed 

( b) Mr. F. L. Hess has called the attention of the writer to crystals from Shooting 
Creek, Clay County, N. C., that are intergrowths of large proportions of rutile with small 
proportions of ilmenite. 

l87 Warren, C. H., The ilmenite rocks near St. Urbain, Quebec; a new occurrence of 
rutile and sapphirine: Amer. Jour. Sci., 4th ser., vol. 33, pp. 263-277, 1912. 

188 Watson, T. L., and Taber, Stephen: Geology of the titanium and apatite deposits 
of Virginia: Virginia Geol. Survey Bull. III-A, p. 257, 1913. 

189 The appearance is very similar to that of the polished surface of the Tuscarora ore 
illustrated by Singewald (op. cit. p. 88), in Plate VII, A., where the light colored bars are 
described as ilmenite. 

1 "Compare Warren’s comments on the intergrowths of ilmenite and hematite in the 
St. Urbain ilmenites: Amer. Jour. Sci., 4tli ser., vol. 33, pp. 266-7, 1912. 

191 Van Rise, C. R..JJ. S. Geol. Survey Mon. 47, pp. 227-228, 1904. 



PLATE XXII. 



{A) Photomicrograph of titaniferous magnetite from Smith exploration, show¬ 
ing alteration of ore mineral (black) into rutile (gray). The whitest portions are areas 
of fibrous silicates. Ordinary light. X100. 

( B ) Photomicrograph of silicates associated with titaniferous magnetite of 
Pennington exploration, Ashe County, N. C., showing probable pseudomorph after 
oblivine. Ordinary light. X60. 

(C) Photomicrograph of titaniferous magnetite from Pennington exploration, 
Ashe County, N. C., showing presence of rutile (gray) in the ore mineral (black). 
The white areas are masses of fibrous silicates. Ordinary light. X81. 

( D) Polished surface of ore. Tuscarora mine, Guilford County, N. C. Black 
is magnetite, and light gray is ilmenite. X2. (Reproduction of Fig. C, pi. II, U. S. 
Bureau of Mines. Bull. 64.) 


202 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

when the original rocks associated with the ores were metamorphosed 
to schists and gneisses which now surround them. 

In the Tuscarora ore the rutile is apparently original, as its particles 
which are often completely embedded in the ore minerals, frequently 
show crystal outlines. Moreover, in a few cases similar crystals are 
embedded in the amphibole that lies between the ore grains. In the 
case of the Tuscarora ore it seems necessary to conclude that the rutile 
was one of the first minerals to form, as it was in the St. Urbain rocks 
and in the rutile-nelsonite of Virginia, being preceded only by the spinel 
which occupies the centers of many of its grains. 

On the assumption that the rutile is a secondary mineral and that 
the magnetite and rutile in the ores together represent the composition 
of an original mineral or mineral intergrowth, the following table has 
been compiled. The proportions of ilmenite and magnetite present in 
22 ores are shown as calculated from the percentages of iron and titanium 
given in the records of their analyses. Of course it is realized that the 
results of such a calculation, as Singewald has stated, are not accurate, 
since the percentage of iron given by analysis is the total iron content 
of gangue and ore. The iron in the gangue is not associated with the 
titanium. Consequently the proportion of titanium in the ore minerals 
is greater than that shown by the analyses. Moreover some of the rutile 
may be primary and may never have existed as part of an ore mineral. 

Ilmenite and magnetite in titaniferous magnetic ores in North Carolina. 






lyses 




Proportions 

Corresponding 







A nil 





to A 

nalyses 


Percent 

ages 


Si0 2 

Fe 

Ti' 

0 2 

Ti 

lime; 

nite 

Magnetite 

Ilmenite 

Magn 

etitc 

1 

. 13 

64 

.56 

4 

.48 

2. 

. 69 

8 

.51 

84 

.85 

9. 1 

90 

9 

1 

46 

65 

32 

4 

80 

2. 

.88 

9 

12 

85. 

.58 

9.6 

90. 

4 

6 

35 

57. 

66 

4 

69 

2. 

81 

8. 

.89 

75 

12 

10.6 

89. 

4 

7 

.91 

53 

.35 

4 

.92 

2 

.95 

9 

.34 

68 

. 95 

11.9 

88. 

1 

5 

. 12 

50 

.77 

4 

.95 

2. 

.97 

9 

.40 

65 

.34 

12.6 

87. 

4 

4 

.72 

52 

44 

5 

.38 

3 

.23 

10 

. 22 

67 

. 23 

13.2 

76. 

8 


. 54 

66 

.95 

6 

.80 

4. 

.08 

12 

92 

85. 

91 

13.1 

86. 

9 

2 

37 

62. 

16 

7. 

44 

4 

.48 

14 

18 

78. 

65 

15.2 

84. 

8 

9 

.90 

46 

,81 

6 

03 

3. 

62 

11 

45 

58. 

.84 

16. 1 

83. 

9 

10 

92 

40 

71 

5. 

54 

3. 

32 

10 

50 

50 

90 

17.1 

82. 

9 

5 

.50 

52. 

80 

8. 

00 

4. 

80 

15 

20 

65. 

19 

19.0 

81. 

0 

4 

35 

52. 

85 

8. 

.80 

5 . 

,28 

16 

.72 

64 

50 

20.6 

79. 

4 

4 

75 

52 

13 

8. 

91 

5 . 

34 

16 

87 

63. 

56 

21.0 

79. 

0 

5. 

37 

51. 

75 

9. 

17 

5. 

50 

17. 

40 

62. 

64 

GO 

fH 

78. 

2 


74 

55. 

61 

13. 

92 

8. 

35 

26. 

45 

63. 

38 

29.4 

70. 

6 

1 . 

80 

51. 

17 

14. 

46 

8. 

68 

27. 

47 

60. 

85 

31.1 

68. 

9 

9. 

25 

39. 

42 

11 

90 

7. 

14 

22. 

58 

42. 

96 

34.5 

65. 

5 

6. 

63 

36. 

00 

15. 

00 

9. 

00 

28. 

48 

35. 

26 

44.7 

55. 

3 

• • 

• • 

37. 

10 

36. 

40 

21. 

81 

69. 

12 

16. 

10 

81.1 

18. 

9 

• 

83 

36. 

26 

37. 

88 

22. 

73 

71. 

94 

13. 

52 

84.2 

15. 

8 

7. 

55 

28. 

24 

41. 

21 

24. 

73 

78. 

27 



100.0a 

0. 

0 

• ■ 

. . 

25. 

76 

38. 

81 

23. 

29 

73. 

71 



100.06 

0. 

0 


a. With excess of TiO s corresponding to about .5% rutile. 

b. With excess of TiO? corresponding to about 1.25% rutile. 




TITANIFEROUS MAGNETITES 


203 


Tlie table is interesting, however, in showing a gradation from ores 
containing titanium equivalent to 9 per cent, of ilmenite through those 
in which the titanium present is equivalent to that in pure ilmenite, 
into those in which the titanium is in excess of this quantity. 

Whenever C r 2 0 3 has been sought in the analyses of North Carolina 
and Tennessee magnetites it has been found in the titaniferous varieties. 
On the other hand, it has not been detected in those containing only 
small quantities of titanium. It is not reported in any of the magne¬ 
tites that are low in Ti0 2 , even in the case of the complete analyses 
published in the Report of the 10th Census. It has been sought for 
by Mr. Fairchild in the ore of the Cranberry mine and by Dr. Hinds in 
that of the Peg Leg mine (pages 102and 127),buthasnotbeenfoundin either. 
Nor was it found in the magnetite associated with marble at Lansing. 
(Page 187.) In the titaniferous ores it is evident that the chromium 
is associated with the magnetite rather than with the ilmenite, since, 
when an ore from the McCuiston place on the Tuscarora belt w T as sub¬ 
jected to the influence of a magnet most of the chromium w r ent with 
the magnetic portion. The anlyses show that w T hereas about 93 per 
cent of the Ti0 2 went into the non-magnetic portion, nearly 77 per cent 
of the Cr 2 0 3 went into the magnetic portion. 

Result of magnetic treatment of ore from the McCuiston place, Guilford County, N. C. 


Silica (Si0 2 ). 

Composition 
of crude 
ore 

12.75 

Composition 
of magnetic 
portion 

1.30 

Composition 
of non-mag- 
netic portion 

20.80 

Iron (Fe). 

41 95 

07.60 

21.63 

Titanium dioxide (Ti0 2 ). . 

15.35 

1.27 

16.20 

Chromic oxide (Cr 2 0 3 ) . . . . 

1.25 

1.43 

.43 

Ilmenite and rutile. 

29.15 

2.42 

30.75 

Magnetite. 

43.12 

92.10 

14.25 


In many, if not all, titaniferous magnetites, wherever found, there 
are notable quantities of chromium. W r atson 192 reports it in both the 
ilmenite and the rutile of the nelsonite district of Virginia. Kemp 193 
declares that “it is possible that chromium oxide, which is generally 
present in titaniferous ores, although rarely determined, may also enter 
into some form of spinel . . and it may be said that at least traces of 
chromium are alsmost invariably present in titaniferous ores,” and 
quotes 194 a number of analyses of chromiferous titaniferous ores to 
substantiate his statement. The two showing the greatest percentages 
of Cr 2 0 3 are from Chugwater Creek, Wyo., and Mayhew Lake, Minn., 
both of which are associated with gabbros. 


192 Op. cit., pp. 107, 119, 194. 

193 Kemp, J. F. t The titaniferous iron ores of the Adirondack's: U. S. Geol. Survey, 
Nineteenth Ann. Kept., pt. 3, p. 390, 1899. 

19 Ubid., pp. 387-388. 








204 


MAGNETIC IRON jORES OF EAST TENN. AND WESTERN N. C. 


Analyses of tita-nijerous magnetite from Chugwater Creek, Wyo., and Mayhew Lake, Minn. 


Silica (Si0 2 ). 

Chugwater 

Creek 

.70 

Mayhew 

Lake 

2.02 

Alumina (Al 2 0 3 ) . 

3.98 

2.08 

Ferric oxide (Fe 2 0 3 ). 

45.03 

J80.78 

Ferrous oxide (FeO). 

17.90 

Manganese oxide (MnO) . 

1.42 


Magnesia (MgO). 

1.50 


Lime (CaO). 

111 


Sulphur (S). 

1.44 


Phosphorus pentoxide (P 2 0 3 ). 

Tr. 

.03 

Chromic oxide (Cr 2 0 3 ) . 

2.45 

2.40 

Titanium dioxide (Ti0 2 ). 

23.49 

12.09 


99.20 99.90 

On the other hand, so far as known, Ti0 2 is not present in the 
chromite of North Carolina, nor is it known to be present generally in the 
chromite of other regions, though it has been found in the chromiferous 
iron ores of Mt. Poon, Greece, where an ore is mined containing 47.50 
—49.10 per cent of iron, 2.19—2.45 per cent of chromium, and 0.45—- 
0.60 per cent of titanium dioxide. 195 These ores are somewhat similar 
to the chromiferous ores of North Carolina in that they are associated 
with large masses of serpentine, either as veins in the serpentine, on the 
contact of serpentine and limestones or in fissures in the country rock. 

Moreover, Kemp concludes from his study of the Adirondack ores 
that vanadium is a characteristic component of the titaniferous varieties. 
It is usually present in less than half of one per cent of V 2 0 5 , but the 
titaniferous magnetites, he declares, are the only magnetites yielding 
more than traces of this oxide. Watson 196 reports it in the rutile and 
ilmenite separated from Virginia nelsonite and remarks that in the three 
specimens analyzed the V 2 0 5 is in excess of the Cr 2 0 3 . He remarks 197 
that Hasselberg 198 found that chromium was present in the rutiles 
studied by him when vanadium was present in appreciable amounts, 
but when vanadium was present in very small amount chromium was 
absent or was present only in traces. In the North Carolina titaniferous 
ores, which are known to contain rutile, the chromium content is com¬ 
paratively large and vanadium is absent. At least this is true of the 
two ores in which vanadium has been sought. 

In view of Kemp’s statements with reference to vanadium it is 
interesting to note that the Helton Creek ore, in North Carolina, though 
it contains 12.96 per cent of Ti0 2 , contains no V 2 0 5 (compare page 214), 
and there is none in the titaniferous ore of Lost Cove, Tenn. Moreover, 


195 Quoted from Cirkel’s Report on the chrome iron ore deposits in the eastern town¬ 
ships, Prov. of Quebec. Dept, of Mines, Canada, Alines Branch No. 29, p. 9, 1909. 

* "Op. cit., pp. 107, 119, 194. 
i^Op. cit., p. 228. 

19 8Hasselberg, B., Chem. News, vol. 76, pp. 102-104, 1897. 



















TITANIFEROUS MAGNETITES 


205 


none was reported by the chemists of the 10th Census in the ore of the 
Dannemora mine, Guilford county, N. C., though in this case the ab¬ 
sence of this oxide from the record may be due to the fact that it was not 
looked for. On the other hand, the magnetite 199 of the Hibernia mine 
in New Jersey, with only 0.54 per cent of Ti0 2 contains 0.14 per cent 
of V 2 0 3 (about 0.17 per cent of V 2 0 5 ), and that of the Richard mine 
with only 0.30 per cent of Ti0 2 contains 0.11 per cent of V 2 0 3 (about 
0.13 per cent of V 2 0 5 ). 

Singewald 200 has already referred to the presence of vanadium in 
the New Jersey ores as controverting Pope’s view 201 that the titaniferous 
magnetites are characterized by the presence of V 2 0 5 in definite ratios 
to their Ti0 2 content and that non-titaniferous magnetites contain none. 
He shows that in the New Jersey ores the ratio of V 2 0 5 to Ti0 2 varies 
all the way between 1 to 3.2 and 1 to 11.9, instead of being always in 
the neighborhood of 1 to 28. If the New Jersey ores are not to be re¬ 
garded as titaniferous since they contain less than 1per cent, of Ti0 2 
their analyses “indicate that a vanadium content is not characteristic 
of the titaniferous ores alone.” The analyses of the Helton Creek and 
Lost Cove ores indicate also that this oxide is not characteristic of all 
titaniferous ores. 

\ 

Analyses of the non-titaniferous ores of the Cranberry and Peg Leg 
mines show no V 2 0 3 . Thus we may fairly infer that presence or absence 
of vanadium in iron ores is more characteristic of the province in which 
the ores occur than of the variety of ore occurring in it. 

The high alumina in many of the ores may be due in some cases to 
corundum and in others to a spinel. A green spinel has been noted in 
the ore of the Tuscarora mine in North Carolina (see page 236), and 
both spinel and corundum in the titaniferous emery on Dobson Moun¬ 
tain (page 225.) Moreover, corundum is known to occur in many of 
the titaniferous ore bodies at various points in the Piedmont Plateau. 

ORIGIN 

The microscopic study of thin sections of the ores and the rocks 
associated with them (cf. pages 209 to 239), indicates very clearly that 
the rocks accompanying the ore-bodies are different from those most 
intimately associated with the non-titaniferous ores of the Cranberry 
type. The rocks accompanying the non-titaniferous ores are pegmatites, 
epidote gneisses, liornblende-epidote schists and masses of hornblende, 
and the ore is mainly a mixture of magnetite and hornblende. Those 
accompanying the titaniferous ores are olivine gabbros and talcose, 

i9»Bayley, W. S., Iron mines and mining in New Jersey: Geol. Survey of N. J. Final 
Report Series of the State Geologist, vol. 7, pp. 112-113, 1910. 

200 Singewald, J. T., Jr., Op. cit. u. 80. 

2 <>iPope, F. J., Investigation of magnetic iron ores from eastern Ontario: Trans. Am. 
Inst. Min. Eng., vol. 29, pp. 395-397, 1899. 



MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


206 


serpentinous and chloritic rocks that in all probability were derived 
from olivine rocks like dunite or peridotite. (See Plate XXII., B.) 
At only one place (Senia, page 218), do we have direct evidence of dn- 
nite with the ores, but at another (Smith’s, page 212), the lean ore 
possesses a structure which suggests that of an olivine rock, and at most 
of the other openings are the talcose, serpentinous and chloritic schists 
that have already been referred to as probably metamorphosed olivine 
rocks. At the Tuscarora mine the rock immediately associated with the 
ore is an olivine gabbro or a hornblende schist that may well be a meta¬ 
morphosed gabbro. At the few places where epidote has been described 
as occurring with the taniferous ores, it is now known to be in the coun¬ 
try rock and not in the gangue. 

The universal presence of notable quantities of chromium in the 
titaniferous ores, and the absence of this metal from the non-titaniferous 
magnetites, indicates a difference in origin of the two. This is further 
confirmed by the universal presence of epidote in the non-titaniferous 
ores and its absence from the titaniferous varieties. The non-titaniferous 
ores are plainly related to pegmatites. The titaniferous ores are not 
so related—or at any rate pegmatites have not been found with them. 
These ores appear to be associated with basic rocks, which elsewhere in 
the State are dunites, amphibolites and olivine gabbros 2 02 , which, where 
well developed, contain corundum, spinel, chromite, and in some places 
rutile 2 03 . The ores always contain titanium, chromium and spinel and 
are in some places associated with corundum (page 232), and at several 
places the mixtures of magnetite, rutile, spinel and corundum, because 
of the large quantities of the last two named minerals present in them, 
are more properly ores of “emery” than of iron. (See page 225.) It 
appears proable that the titaniferous magnetites, for the most part, are 
connected genetically with apophyses from dunite and peridotite mag¬ 
mas that have intruded the schists along their foliation planes in the 
form of narrow veins or flat lenses. The ore veins are portions of these 
rocks rich in ferruginous material. The ores correspond in this respect 
to ores of the same kind found associated with gabbros in the Adiron- 
dacks or with rocks closely related to dunite in Rhode Island and else¬ 
where, where they have been regarded generally as magmatic segrega¬ 
tions. They probably belong to the injected orthotectic magmatic 
deposits of Lindgren. 204 In North Carolina, however, some of the ores 
are apparently in distinct dykes or in parallel walled veins of compact 
titaniferous magnetite, and these may have been deposited by hydro- 
thermal processes. At Senia the ore is distinctly later than the dunite 
in which it occurs, and in the sections of the Smith and Pennington ores 

202 Pratt, J. H., and Lewis, J. V., North Carolina Geol. Survey, vol. 1, pp. 369-384, 1905. 

203 Pratt, J. H., and Lewis, J. V., Op. cit., pp. 277, 279, 280. 

204 Lindgren, Waldemar: A suggestion for the terminology of certain mineral denosits 
Econ. Geol., vol. 17, p. 292, 1922. y 




TITANIFEROUS MAGNETITES 


207 


the ore minerals are younger than the original silicates associated with 
them. Consequently they cannot have been deposited by segregation 
from a magma the greater portion of which was still liquid, but must 
have been intruded into the solidified components of the magma. 


UTILIZATION 

Singewald 205 has shown that for the most part the titanium in 
titaniferous magnetic ores is due to such an intimate intergrowth of 
some titanium mineral (rutile or ilmenite) with magnetite that their 
separation is not practicable on an economic scale and that therefore 
their titanium content cannot be reduced to within the limits acceptable 
to the blast-furnace men. 

Among the few deposits that might possibly be utilized as a source 
of concentrates sufficiently low in titanium to be acceptable are those 
on the Tuscarora and Shaw belts in Guilford and Rockingham counties, 
N. C. (page 234). A specimen of the ore of the Tuscarora mine, con¬ 
taining in its crude condition 12.82 per cent of Ti0 2 was crushed to 
pass through a 50 mesh screen and separated by a magnet into two 
parts. The magnetic portion comprising 71.5 per cent of the original 
ore was found to contain only 4.25 per cent of Ti0 2 , while the non¬ 
magnetic portion comprising 28.5 per cent of the original ore contained 
34.32 per cent of Ti0 2 . “Although the titanium content of the con¬ 
centrate is still higher than is acceptable in present blast-furnace prac¬ 
tice, the concentrate is so high grade that it would make an acceptable 
ore to mix with titanium-free ore. 2 0 6 . Rut we know very little as to the 
quantity of ore available. “Such conclusions as can be drawn from 
old data and the nature of the deposits are not very favorable to them. 
The ore bodies seem to be rather small and irregular in distribution, 
so that mining operations would be attended by considerable uncer¬ 
tainty." 

No examination was made by Singewald of any of the titaniferous 
ores of Ashe, Mitchell or Avery counties in North Carolina, or of Carter 
County, Tennessee, but the study of their thin sections by the present 
writer indicates that their titanium content is due partly, if not entirely, 
to the presence of rutile. This might be separated from the magnetite 
by magnetic concentration after pulverization, if there were any incen¬ 
tive to make the attempt. However, none of the deposits in any of 
these counties is large enough to warrant the installation of concentrating 
machinery so long as the numerous non-titaniferous deposits remain 

undeveloped. 

2 t)-SingewaId, J. T., Jr., U. S. Bur. Mines Bull. 04, 1913. 

206 Singewald, J. T., Jr., Op. cit., p. 89, 91. 





208 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


RESERVES 

No detailed estimate of the quantity of titaniferous ores in western 
North Carolina and East Tennessee has been attempted because of 
the difficulty of using them in the blast-furnace. There is, unquestion¬ 
ably, a large tonnage of these ores in the mountains and perhaps a larger 
tonnage in the Piedmont area, but with the exception of the deposits 
in the Tuscarora and Shaw belts in Rockingham, Guilford and Davidson 
counties in North Carolina, all the ore-bodies are small. None of them, 
so far as known, would yield tonnages large enough to offer opportunities 
for cheap mining, and consequently none of them are to be regarded as 
promising available ore in the near future, even if the objection to their 
titanium content might be overcome. 


CHAPTER XI. 


MINES AND PROSPECTS IN TITANIFEROUS 

MAGNETITES 

GENERAL STATEMENTS 

It has already been stated that none of the titaniferous ores in 
either North Carolina or Tennessee are now being worked. All of the 
openings upon them, whether they were mines or only small prospect 
pits, have filled with wash so that the relations of the ore bodies to the 
surrounding rocks cannot be studied. 

The deposits of all the ores in western North Carolina and East 
Tennessee that have been referred to as containing titanium in large 
quantity are described briefly. They are grouped according to county, 
and if two or more occur on the same structural belt, these are described 
in succession. 

DEPOSITS IN THE MOUNTAIN DISTRICTS 

ASHE COUNTY, N. C. 

DISTRIBUTION 

The magnetites and titaniferous magnetites in Ashe County, have 
been grouped by Nitze 207 in three main belts. (See map, Figure 13.) 
The deposits, he states, 

“occur distributed over a rather undefinable area, though there is some regularity in 
the direction of their outcrops, which have a general trend northeast and southwest.” 

The three main belts recognized by Nitze are (1) the Ballou or 
River Belt to the east (page 135), (2) the Red Hill or Poison Branch 
Belt about 2j^ miles farther west, and (3) the Titanifercus Belt, about 
3 miles northwest of the Poison Branch Belt. Deposits of titaniferous 
ores are confined to the western belt. According to Nitze this starts at 
the northern edge of the county, near the Virginia State line, on the 
waters of Little Helton Creek and extends southwesterly to Helton 
Creek, near Sturgill P. O., a distance of 2^ miles. Since the ore of 
the Kirby mine (page 136), which is at the southwest end of Nitze’s 
belt contains very little Ti0 2 , it would seem best to terminate the belt 
with the Pennington opening which is just north of Wallen’s Creek. 
The Pennington deposit is 1}/% miles from the McCarter prospect which 
is the next one farther to the northeast, with no evidence of others be¬ 
tween the two, and the Bauguess deposit (see map, Figure 13.) which 
is regarded as on the same belt between the two, is nearly one-half mile 

207Nitze, H. B. C., Iron ores of North Carolina: North Carolina Geol. Survey Bull. 1 
p. 132, 1893. ’ 




210 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

southeast of the line joining them. The titaniferous belt in Ashe county 
is not a structural belt but is merely a convenient grouping of deposits 
for purposes of description. 

Smith Place 

About a quarter of a mile east of Little Helton Creek and the same 
distance south of the State line are 3 openings on property now owned 
by Wm. Smith. The eastern one is referred to by Nitze 208 as being on 
the property of Wm. Young and the other two on the land of G. C. 
McCarter. 209 Shippey Branch separates the two properties. 

Nitze describes Mr. Young's property as follows: On the hill between 
Shippey Branch and the Jefferson-Marion road a “very heavy outcrop 
of magnetite extends E. and W. along the crest of the ridge covering a 
width of at least 25 feet." The ore is a coarse granular magnetite, 25 
feet wide and almost free from gangue. He gives two analyses of se¬ 
lected specimens. These are: 

Partial analysis of titaniferous magnetite from Smith place, Ashe County, N. C. 

l 2 

Silica (Si0 2 ). 5.12 4.35 

Iron (Fe). 50.77 52.85 

Sulphur (S). .04 . 

Phosphorus (P) . .005 .013 

Titanium dioxide (TiO*). 4.95 8.80 

Phosphorus ratio (P:Fe). .009 .024 

Since Mr. Nitze’s visit to the property a pit has been sunk on the 
top of the hill. At present only the dump can be seen. On this are 
fragments of a lean ore composed of magnetite, mica, and augite or 
hornblende, and of a rich ore that consists almost exclusively of magne¬ 
tite. The ore resembles very closely that at the Pennington place (see 
page 216), but it possesses a slight purplish tinge. It is fine-grained and 
granular, and is apparently made up largely of little crystals of magnetite 
in a mixture of magnetite and a green serpentinous mineral. No gangue 
was seen, nor was the relation of the rich ore to the lean ore observed. 

Under the microscope thin sections of this ore are discovered to be 
composed of a weakly polarizing material in elliptical areas (Plate 
XXIII, A), large shattered grains of an opaque mineral, probably mag. 
netite, and of an intergrowth of magnetite and reddish yellow rutile- 
(Plate XXIII, B and XXII, A). Through this runs a brightly polar¬ 
izing mass which is apparently a crush-debris since it sends arms into 
the cracks in the magnetite. Under high powers this is resolved into 
an aggregate of small plates and fibers of a colorless micaceous mineral, 
magnetite dust and small crystals and a few comparatively large flakes 
of brown biotite. The weakly polarizing material is of two kinds. Both 


208 Op. cit., p. 158. 
209 Op. cit., p. 159. 











PLATE XXII1. 




(A) Photomicrograph of titaniferous magnetite from Smith exploration, Ashe, 
County, N. C., showing cracked magnetite. The gray groundmass is composed of 
fibrous silicates. Between crossed nicols. X50. 

( B ) Photomicrograph of another part of the same ore, showing rutile (gray), 
in magnetite (black). The white areas represent fibrous silicates. Ordinary light’ 



212 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

are composed mainly of a light-green, fibrous, chloritic mass, but in one 
kind there are a few sharp edged grains and many minute spicules of a 
doubly refracting mineral that is so thoroughly enmeshed with green 
fibers that its character cannot be determined, and an abundance of 
magnetite particles. The other contains almost no magnetite but, on 
the other hand, there are present in it many tiny crystals of rutile. 
Both are mainly in round and elliptical areas outlined by magnetite 
dust, but in most places the material extends beyond these outlines in 
all directions between neighboring magnetite grains, and in the cracks 
between their dissevered portions. If the streaks of magnetite dust 
mark the boundaries of some mineral that has since disappeared, the 
shapes of this mineral were similar to those of olivine crystals. (Plate 
XXII, B.) 

Most of the opaque mineral is apparently fresh. At least it exhibits 
no signs of alteration. Some of it, however, is intergrown with rutile 
in such a way as to suggest alteration. In some pieces the rutile occurs 
in irregular patches through the apparently unaltered mineral and in a 
narrow zone around its periphery. In other pieces the interior patches 
coalesce into elongate masses that are in parallel arrangement. (Plate 
XXII, A, B, C, and D.) Often they show crystal terminations, but fre¬ 
quently they are merely aggregates of grains. The appearance is as 
though alteration had proceeded along definite planes in some pieces, so 
that they become an interlayering of wide plates and narrow magnetite 
plates, and finally, as alteration proceeded to completion, into an ag¬ 
gregate of rutile crystals intermingled with a few irregular grains of 
magnetite. A very little light-green polarizing mineral may be present 
with the rutile, but it is insignificant in amount. The pieces of the 
opaque mineral that have appeared to change may have been com¬ 
posed originally of layers of ilmenite in magnetite, or may perhaps 
have consisted wholly of ilmenite, while those pieces that have not 
changed may be magnetite, as the contact between the altered and un¬ 
altered pieces is rather sharp. Singewald (cf. page 32) showed that 
many titaniferous iron ores are intergrowths of thin ilmenite laminae in 
magnetite, and it might well be that in the present instance the ore was 
a mixture of grains of such an intergrowth with grains of ordinary mag¬ 
netite. That the whole mass of the ferriferous mineral in the rock is not 
as rich in titanium as the altered grains might suggest, is indicated by 
the fact that the total TiO 2 content of the ore as shown by analysis is 
only one-ninth that of the Fe 3 0 4 . 

The structure of the ore suggests that of a peridotite which had been 
crushed in places and altered. It was apparently not unlike that at 
Senia (see page 218), near Cranberry, where the unaltered rock contain¬ 
ing the ore veins is a dunite. 


MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 213 

Nitze 210 traced the Smith vein westward across Shippey Branch 
to the land then owned by Mr. McCarter. On the east slope of the hill 
just west of the stream a layer from 9 to 12 feet thick was exposed and 
across the hill just above Little Helton Creek it was again exposed. 
The ore from the eastern exposure analyzed: 

Silica (SiCh). 5.37 Titanium dioxide (Tith). 9.17 

Iron (Fe). 51.75 Phosphorus ratio (P:Fe).034 

Phosphorus (P).018 

The vein was reported as dipping vertical and the country rocks 
were described as pyrophyllite schists. 

This vein has been opened by several pits. Near the western one 
is an exposure of talcose schist cut by irregular veins of pegmatite. 
Most of the schist may be a sheared granite or granite prophyrv; but 
other specimens more closely resemble a sheared rhyolite or tuff. Nearby 
where the road crosses Little Helton Creek are exposures of a dark schist 
that may also be a sheared volcanic rock a little more basic than rhyo¬ 
lite. The pits, though comparatively recent, have fallen in, but their 
large dumps show many fairly fresh fragments of ore and rock. The 
ore is very much like that at the Smith place, but it is denser and more 
homogeneous and therefore not so granular. It has, however, the same 
glistening luster and apparently is similar to it. The rock associated 
with the ore is a biotite-chlorite-actinolite schist, and the lean ore is a 
more massive phase of the same rock in which there is much magnetite. 

Very little can be learned from the thin sections of either ore or 
rock. The latter is light-gray, with small flakes of brown biotite and 
little particles of pyrite in a streaked mass of plagioclase and a grayish- 
green fibrous mineral with here and there a prism of actinolite or an- 
thophyllite. In thin section it appears as an aggregate of poorly de¬ 
fined decomposition products in which lie large masses of a mixture of 
kaolinite, actinolite, chlorite and remnants of plagioclase, comparatively 
large flakes of a brown biotite and many remnants of a colorless pyrox¬ 
ene partially altered to actinolite. All the original components are 
broken into sharp-edged fragments and between them is a matrix of 
kaolin and colorless epidote embedded in feldspathic material with here 
and there a little quartz. A few large prisms of apatite, grains of pyrite 
and clumps of limonite are embedded in this. It is almost impossible 
to reconstruct the original rock from the study of the sections mainly 
because its structure has been completely obscured by the crushing to 
which it was subjected and the alteration of its components to secondary 
substance; but because of the absence of all but small traces of quartz, 
it is probably safe to assume that it was basic. 

The sections of the ore show a rock that is even more completely 
decomposed than that just described. It consists largely of magnetite, 


210 Op. cit., p. 159. 









214 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

which is in fragments with sharp corners. In some specimens a large 
mass is merely sliced and the slices are slightly displaced. In other 
specimens large areas in the section are occupied by many small frag¬ 
ments lying in all positions. Most of the mineral is changed in places 
to limonite and in some grains rutile is present as small irregular masses 
that appear as patches on the opaque magnetite. A few wisps of w r hat 
was originally brown biotite are also present, but they are common only 
along the schistosity planes. They are now largely limonite. Sur¬ 
rounding the magnetite and biotite is a mass of fibrous minerals, among 
which may be recognized light-colored amphibole, epidote and chlorite 
and a large quantity of a very finely fibrous material that is probably 
serpentine. The serpentine forms a felt in which the others lie, and 
occurs also as veins separating the fragments of magnetite. The amphi¬ 
bole is intermingled with numerous small particles of magnetite forming 
masses that may have been pieces of crushed pyroxene, and in some 
places there are curved lines of magnetite particles surrounding a felt 
of almost pure serpentine that may mark the outlines of what were 
originally olivine crystals. (Plate XXII, B.) As a whole, however, 
the rock was so completely shattered, and later so thoroughly decom¬ 
posed that very little of its original structure is now recognizable. It 
was certainly basic and probably olivinitic. 

An analysis of a sample of rich ore from the eastern pit was made 
by J. G. Fairchild of the U. S. Geological Survey with this result: 

Analysis of titaniferous magnetite, near Helton Creek, Ashe County, N. C. 


Silica (Si0 2 ). 5.73 

Alumina (A1 2 0 3 ). 1.70 

Ferric oxide (Fe 2 0 3 ). 45.51 

Chromic oxide (Cr 2 0 3 ).39 

Ferrous oxide (FeO). 2G.20 

Manganese oxide (MnG).34 

Magnesia (MgO). 3.99 

Titanium dioxide (Ti0 2 ). 12.90 

Phosphorus pentoxide (P 2 0 5 ). Tr. 

Sulphur (S). Tr. 

Water at 110° (H 2 G—). 2.81 

Water above 110° (H 2 0-f).0G 


99 . G9 

There are present also traces of CaO, Na 2 0, and lv 2 0. Special 
tests were made for C0 2 , V 2 0 3 , BaO, SrO, and F, but none were found. 

Even if we assume that all of the FeO not required by the Fe 2 0 3 
to make magnetite is present in ilmenite there is, nevertheless, an excess 
of 6.7 per cent Ti0 2 present which is probably rutile. On this assump¬ 
tion the sample consists of about 66.2 per cent magnetite, 12.1 per cent 
of ilmenite, 6.7 per cent of rutile, and 15 per cent of silicate and water. 















MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 215 

1 he specimen analyzed is a fine-grained aggregate of small grains 
of magnetite with here and there a little green chloritic interstitial sub¬ 
stance. The magnetite has a faint tinge of garnet color, so that its 
luster resembles somewhat that of rutile. 

McCarter place 

At the McC arter place the two openings, described by Nitze 211 as 
existing about one-half mile west of the Smith openings and on the north 
side of the highway from Sturgill, have entirely disappeared. The 
property which is now occupied by Mr. Thomas is under cultivation. 
The old openings have been filled and plowed over until no trace of them 
remains. Nitze reports that the eastern opening was a shallow trench 
that uncovered 3 feet of ore “in hornblende, partially altered to as- 
bestus. The western opening, 300 or 400 yards farther west, was on 
an outcrop exposing a thin backbone of ore not more than one foot wide. 

He quotes analyses of two samples from the eastern opening as 
follows: 


Partial analyses of ore from McCarter place, Ashe County, N. C. 


Silica (SiO L >). 

Iron (Fe). 

Sulphur (S). 

Phosphorus (P) . 

Titanium dioxide (TiCF). 
Chromic oxide (Cr 2 0 3 ) . 
Phosphorus ratio (P:Fe). 


1 2 

9.90 10.92 

46.81 40.71 

.137 .0G5 

.025 .012 

G.03 5.54 

.630 . 

.053 .029 


Bauguess place 

At this place the old opening is now almost unrecognizable. It is 
near the top of the northeast slope of the hill between Little Helton and 
Wallen’s creeks and half a mile south of the road from Sturgill to Little 
Helton Creek. Nitze 212 states that a small cut exposed 5 feet of ore 
having a reddish streak in a gangue of epidote, feldspar and quartz. 

Two selected specimens gave: 

Partial analyses of selected samples of ore from Bauguess place, Ashe Comity, N. C. 



1 

2 

Silica (Si0 2 ). 

_ 6.35 

7.91 

Iron (Fe). 

.... 57.GG 

53.35 

Sulphur (S). 

. ... .0G1 

.078 

Phosphorus (P) . 

. . . .008 

. 022 

Titanium dioxide (Ti0 2 ). 

.. 4.690 

4.920 

Chromic oxide (Ci^Ch) . 

... .505 


Phosphorus ratio (P:Fe). 

. . .013 

.041 


211 Op. cit., p. 159. 

212 Op. cit., pp. 159-160. 


















MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


216 


Pennington opening 

The C. Pennington opening is a pit on top of a low hill overlooking 
Wallen’s Creek. It is about 1^ miles southwest of the McCarter 
place and about half a mile northwest of Mr. Pennington’s house. Near 
the pit is a small ledge of hornblende, but no other rocks are exposed in 
the immediate vicinity of the hole. On the road to the east are fairly 
massive schists striking N. 20° E. and dipping high to the southeast, 
that are not unlike those on Helton Creek south of the Kirby mine at 
Sturgill. 

Nothing can now be seen but the dump on which are pieces of ore 
composed of hornblende and magnetite. Nitze 213 declares that the ore 
consists of an 8-foot wide vein of a fine-grained, compact, steel-gray, 
granular magnetite with a little gangue which is generally epidote. 
He gives no further details. 

Analyses of three specimens, probably of selected samples, gave 
the following results: 

Partial analyses of ore from Pennington opening, near Sturgill, Ashe County, A. C. 



1 

0 

/w 

3 

Silica (SiO>). 

4.75 

4.72 

5.07 

Iron (Fe). 

52.23 

52.44 

52.45 

Sulphur (S). 

. 112 

.077 

.... 

Phosphorus (P) . 

.012 

.004 

.022 

Titanium dioxide (TiCC). . . . 

8.91 

5.38 

9.11 

Chromic oxide ((T 2 O 3 ) . 

1.19 


.... 

Phosphorus ratio (P:Fe). . . . 

.010 

.007 

.042 


The ore picked from the dump shows no epidotic gangue. It is 
very much like that of the mine of the old McCarter place, west of Ship- 
pey Branch (see page 215). It consists of broken, fresh magnetite 
fragments, others that are now composed of interlayered yellow and red 
rutile and magnetite, or ilmenite, and a mass of light-green fibers and 
plates, which in some places constitutes oval areas that are almost 
isotropic, and in others a kind of interstitial weakly polarizing aggregate 
with great numbers of brightly polarizing green fibers scattered through 
it. (See Plate XXII, B and C.) Some of the fibrous aggregate has a radial 
structure as though representing the alteration of a primary mineral 
grain, while the rest is a confused aggregate which surrounds the more 
definite areas as though representing a matrix. Through all of the 
material, whether in definite areas or not, there are numerous little 
clumps and prisms of rutile and tiny grains of magnetite. The fibers 
of weakly polarizing aggregate, which may be some variety of chlorite, 
are often arranged perpendicular to the peripheries of the large magne¬ 
tite grains and perpendicular to the walls of the cracks that are so nu¬ 
merous in them. Evidentlv the fibrous material is entirely secondary, 


213 Op. cit., p. 160. 









MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


217 


but the characters of the minerals from which it was derived are not 
certainly known. It is probable, however, that the original rock was 
basic, probably very much like that at the Smith place. 

ALLEGHANY COUNTY, N. C. 

In Allegheny County, which adjoins Ashe County on the east, a 
zone of hornblende schist, often altered to steatite or soapstone, and 
carrying crystalline grains of titaniferous magnetite, which in some places 
is concentrated into workable ore beds, crosses the State line at a point 
about 3 miles west of the east line of the county and follows the Little 
River south westward. 214 

Where concentrated into lenses the magnetic ore is a coarse or fine¬ 
grained, lustrous, granular mass with a steatite or an asbestus gangue. 
Analysis 215 of a sample from the Carrico farm at the north end of the 
belt gave: Silica (Si0 2 ), 6.20 per cent, iron (Fe), 54.72 per cent, sul¬ 
phur (S), 0.038 per cent, phosphorus (P), 0.047 per cent, and titanium 
dioxide (Ti0 2 ), 4.860 per cent. The belt is bordered on the northwest 
and on the southeast by quartz zones carrying a little menaccanite. 

The steatite impregnated with magnetite continues for 6 or 7 miles 
farther southwest and at several places is said to be bordered on both 
sides by quartz and hornblende schist. Below the lower hornblende 
schist is another steatite layer that is magnetitic, but nowhere is the 
magnetic mineral known to be concentrated into workable deposits. 
About 9 miles farther southwest 21 *, and half a mile east of the mouth of 
Pine Swamp Creek, however, there is a heavy outcrop of the magnetitic 
soapstone on the farm of H. Crouse, where a fragment of compact ore 
was found to contain silica (Si0 2 ), 3.08 per cent, iron (Fe), 57.54 per 
cent, chromic oxide (Cr 2 0 3 ), 11.05 per cent, sulphur (S), 0.016 per cent, 
and phosphorus (P), 0.007 per cent. No titanium was reported. 

Southwest of this point the steatite rock is lost and magnetite de¬ 
posits show neither high titanium nor chromium. 

Nitze gives no description of the “quartz” or the “hornblende 
schist” associated with the ore nor of the relations of these rocks to the 
“steatite.” It is significant, however, that the ore is associated so closely 
with a rock that is quite different from the rocks that accompany the 
non-titaniferous ores. 

AVERY AND MITCHELL COUNTIES, N. C. 

DISTRIBUTION 

In Avery and Mitchell counties Nitze 217 describes a belt of titan¬ 
iferous ores as lying from 3 to 5 miles south of the Cranberry non-titan- 


2i4Nitze, H. B. C., Op. cit., p. 125. 
215 Idem., p. 126. 

2i«Idem., p. 128. 

2i?Op. cit., pp. 182-183. 



218 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

iferous belt and generally parallel to it. He states that it begins at the 
mouth of Roaring Creek, 7 miles west of south of Cranberry, crosses 
near the head of Old Cabin Branch, then trends northwest over Grassy 
Bald Ridge, where it passes into Tennessee. 

“The belt traverses the edge of Tennessee for a distance of about 4 miles, bending 
gradually towards the southwest and crossing into North Carolina near the headwaters 
of Big Rock Creek . . . ; thence it continues in a generally southwesterly direction 
across the Roan High Bluff and Fork Mountain, and along the waters of Big Rock 
Creek, to the Yancey county line at Toe River, a distance of about 9^2 miles. 

No reason is given by Nitze for supposing this line to be continuous, 
or even to be a definite series of discontinuous lenses. At its eastern end 
the course ascribed to it crosses the structure af the country, and its 
direction does not correspond with the strike of the veins supposed to 
comprise it. 

Senia deposit 

At the mouth of Roaring Creek on the land of the Toe River Land 
and Mining Co., Nitze 218 found some shallow openings in an altered 
olivine rock showing streaks or seams of magnetite not over two inches 
thick. 

There is at this place a small strip of massive dunite that is sheared 
in places to a chlorite-talc schist. In this is a vein of magnetite mixed 
with a little pyrite. The vein as a whole is made up of a series of twist¬ 
ing veinlets each of which is not more than an inch or so wide, but which 
together constitute a stoekwork about 8 inches wide. At the time of 
the writer’s visit there was little to see at the pit which was full of 
water. The ore is a fine-grained, glistening variety like the titaniferous 
ores elsewhere. 

The dunite is a fine-grained, yellowish-green rock which under the 
microscope is resolved into an aggregate of olivine and a very light green 
tremolite, a little antigorite and a few grains of a very pale chlorite or 
serpentine. Between these minerals are small areas of a structureless, 
green, faintly polarizing material that may be serpentine and here and 
there are clumps of skeleton-groups of magnetite or chromite surrounded 
by a corona of serpentine plates. The section is almost a duplicate of 
that of a dunite pictured by Pratt and Lewis 219 from Shooting Creek, 
Clay county. 

The country rock surrounding the serpentine is Roan gneiss, which 
consists largely of layers of a dark, massive rock that looks like a fine¬ 
grained diabase. A very fine-grained phase of this rock resembles in 
appearance a baked shale. Under the microscope its section shows 
mainly a fine-grained aggregate of little equi-dimensional grains of green 


218 Idem., p. 182. 

219 Pratt, Jos. H., and Lewis, J. V., Corundum and the peridotites of western North 
Carolina: North Carolina Geol. Survey, vol. 1, pi. 35, fig. 1, 1905. 



MINES ANI) PROSPECTS IN TITANIFEROUS MAGNETITES 


219 


hornblende and unstriated feldspar. The small triangular spaces be¬ 
tween the grains are occupied by quartz, and embedded in the aggregate 
are large garnet masses made up of numerous small grains of about the 
same size as those of the hornblende-feldspar aggregate. There is also 
present a very little magnetite, which appears only as an interstitial 
filling between amphibole grains. 

Avery place 

The other deposits on this belt have been worked so slightly that 
they offer little opportunity for study. At the Avery place, on the 
southwest slope of Big Yellow Mountain, near the head of Old Cabin 
Branch about 2 3^ miles north of Roaring Creek is an old hole and a 
dump on which are some fragments of a very rusty rock that may be a 
phase of the Roan gneiss. No ore is now to be seen. 

Nitze 22 0 declares that “the country rock is a very coarse-grained 
pegmatite, hornblende schist, epidote and garnet rock dipping towards 
the northeast. The ore is a highly lustrous, titaniferous magnetite, 
compact, homogeneous and free from gangue. It occurs in thin irre¬ 
gular seams and lenses from 2 inches to 2 feet in thickness.” He states 
that at the time of his visit all the ore had been removed and attempts 
to find other lenses had failed. Nevertheless, he gives two analyses of 
selected samples as follows: 


Partial analyses of ore from Avery place, 

Avery County, 

N. C. 


1 

2 

Silica (SiO- 2 ). 

1.46 

.54 

Iron (Fe). 

65.32 

66.95 

Sulphur (S). 

.025 

.00 

Phosphorus (P) . 

.009 

.015 

Titanium dioxide (TiCh). 

o 

GO 

6.80 


As no rocks were seen during the writer’s hurried visit to the place 
Nitze's observations can neither be contradicted nor confirmed. It is 
noteworthy, however, that no gangue was seen with the ore. 

Grassy Bald of Roan Mountain 

The next point on this supposed belt at which ore is known to 
occur is at the summit of Grassy Bald of Roan Mountain where there 
is a very different ore from any other observed in the two States. The 
country rocks on the southeast side of the knob are banded massive 
and schistose Roan gneisses cut by pegmatite. The massive gneiss 
resembles a very slightly schistose fine-grained gabbro and the schistose 
varieties differ from this only in their greater schistosity. 

At the pits, which are on top of the mountain, are dumps on which 
are fragments of a coarse pegmatite made up mainly of biotite and feld- 


22°Op. cit., p. 182. 










220 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

spar, with very little quartz, and containing here and there large irregular 
masses of grayish, brilliantly lustrous magnetite or nests of magnetite 
and biotite. The quartz and feldspar are thoroughly crushed and the 
magnetite and biotite appear to penetrate the crushed masses. No 
evidences of the presence of definite veins of magnetite were seen. All 
of the magnetite appeared to be in the form of irregular constituents 
of a pegmatite. Mr. Hamilton reports the pegmatite as extending 
across the mountain in a nearly east-west direction. 

Evidently the ore here is quite different from that at Cranberry. 
It apparently is different also from that on the Avery place and at 
Senia. A test made for titanium by Geo. Steiger of the U. S. Geological 
Survey laboratory showed the presence of about 2 per cent of titanium 
dioxide (Ti0 2 ). As might have been suspected from its association with 
pegmatite this ore does not belong with the more usual types of the 
titaniferous magnetite. 


Jenkins prospect 

The main Jenkins openings are on Road Ridge about 2j^ miles 
above the mouth of Greasy Creek, a tributary of Rock Creek, and 1 
mile south of the line between North Carolina and Tennessee. They 
are in a non-titaniferous magnetite (see page 130). Other openings 
higher on the ridge, however, are in titaniferous ore 221 . One of these, 
350 feet above the creek, shows a very compact lustrous ore free from 
gangue. This ore is said to be in a vein 5j^ feet thick. The second 
opening, near the summit of the ridge, is in a streak of ore that is 1 foot 
thick at the surface and 5J4 feet thick at the bottom of the cut. In its 
“upper part the ore has small quartz grains porphyritically enclosed, 
but lower down it is free from this admixture, being very pure, homo¬ 
geneous and highly magnetic.” The wall rock is reported by Nitze to 
be hornblende gneiss and pegmatite. 

An analysis of a mixture of samples from the two pits gave: Silica 
(Si0 2 ), 6.58 per cent, iron (Fe), 54.48 per cent, sulphur (S), 0.023 per 
cent, phosphorus (P), 0.033 per cent, and titanium dioxide (Ti0 2 ), 
4.96 per cent. 

These two deposits are not in the belt of titaniferous ores outlined 
by Nitze, but are about 4 miles west of it. On Keith’s Roan Mountain 
map they are located in an area of Cranberry granite. Unfortunately 
the openings have so badly caved that it is impossible to learn whether 
the rocks immediately associated with the ores are basic or not. The 
country rock is a series of schists and pegmatites that resemble in some 
places more nearly the Carolina gneiss than the Cranberry granite. 


221 Nitze, H. B. C., Op. cit., p. 181. 



MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 221 

Other deposits 

The remaining deposits placed by Nitze in this belt are at its south¬ 
west end, where a few pits have uncovered ore containing titanium, 
but in no cases are the geological relations of the ore-bodies known. 
On the north side of Little Rock Creek, half a mile from its junction 
with Big Rock Creek, a small pit is described 222 as exposing an ore lens 
about 3 feet across, on the land of Joel Gouge. At the depth of 4 feet 
it is entirely cut by a trap dike, which Nitze states accompanies the 
formation all the way south to Toe River. The ore is dark red and 
homogeneous, thus being unlike the other ores in the belt, but Nitze 
ascribes this peculiarity to the presence of the dike. The strike of the 
gneisses at the pit is N. 40° E. On Keith’s map this area is mapped 
as being underlain by Cranberry granite. 

Analysis of the ore showed: 

Partial analyses of ore from land of Joel Gouge, Mitchell County, N. C. 

Silica (SiOo). 1.13 Phosphorus (P).078 

Iron (Fe). . ... 64.56 Titanium dioxide (TiCB) . 4.48 

Sulphur (S).027 

Other deposits of similar ore are said to be at Jas. Herren’s on 
Pepper’s Creek, a quarter of a mile from Rock Creek, and 3 miles farther 
southwest on the property of Irwin Hughes, half a mile above the mouth 
of Rock Creek, but at neither of these places could anything definite 
be learned as to the character of the ore, or of its associated gangue. 

The Herren deposit on Pepper Creek may be that on the land of 
Miles Herren, at Pepper P. O. Here there is an opening on the top of 
a hill just north of the road, on which are exposures of Roan gneiss that 
looks very much like a sheared basic porphyrite. Nothing can be seen 
in the holes. Nitze reports the vein to be 6 feet to 8 feet thick. The 
dump is also overgrown but the few specimens of ore taken from it 
resemble the lustrous crystallized ore seen elsewhere. 

The farm of Irwin Hughes was not found; but in about the same 
location, on the land of M. C. Bailey, are some old holes which are now 
filled with soil. One piece of ore picked from the soil where the old 
dump is said to have been, is a black massive homogeneous magnetite 
% that lacks the high luster of the titaniferous phases. If the location of 
the holes is correct the surrounding rock is Cranberry granite. 

The only other deposit of titaniferous magnetite known to occur 
in Mitchell county is indicated by float near the head of Wadkins Branch, 
on the south slope of Pumpkin Patch Mountain about 2 miles north of 
west from Bakersville 223 . An analysis of specimens picked from the 
surface showed the presence of 4.56 per cent of titanium dioxide and 
57.98 per cent of iron. 


222 Nitze, II. B. C., Op. cit., p. 183. 
223Nitze, H. B. C., Op. cit., p. 184. 










MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


OOC) 


“Similar traces of float ore have been found along the southern 
slope of the mountain range in a westerly direction for 4 miles to Red 
Hill, and in an easterly direction for lJdj miles, but no developments 
have been made.” 224 


CARTER COUNTY, TENN. 

Lost Cove prospect 

The deposit on which this prospect was opened is described by 
Hamilton 225 as being on the land of David Street, on the west side of 
the ridge between Burbank and Lost Cove. Its more exact location 
is not given but it is probably the prospect mapped by Keith 226 about 1 
mile southwest of Burbank, in which case it is on the belt designated by 
Nitze as south of the Cranberry mine belt and parallel to it. On Keith’s 
map the pit is shown in an area of Cranberry granite, but Hamilton 
states that it is in Roan gneiss. The hole is now filled and the only 
specimens of the ore obtainable were found as fragments in the soil. 

Analyses of two samples were made by Dr. J. I. D. Hinds of the 
Tennessee Geological Survey. 


Partial analyses of ore from Lost Cove, 

Carter County, 

Tennessee. 


1 

2 

Silica (SHU). 

1.46 

4.80 

Alumina (ALO 3 ). 

1.60 

3.28 

Iron (Fe). . .'. 

56.00 

51.74 

Titanium dioxide (Ti0 2 ). 

10.50 

17.20 

Phosphorus pentoxide (Po() 5 ). 

1.97 

Tr. 


In sample No. 2 special tests were made for zinc, tantalum, tungsten, 
vanadium, calcium, copper and tin but none were found. 

A complete analysis of a third sample of the same ore was made by 
Mr. F arrar of the same Survey, and determinations of ferrous and ferric 
iron and of titanium dioxide in a fourth sample. Mr. Farrar’s results 
were: 

Analyses of titaniferous magnetite from Lost Cove, Carter County, Tenn. 



1 

2 

Silica (Si0 2 ). 

0.18 


Ferric oxide (Fe 2 03 ). 

Alumina (ALO 3 ). 

47.92 

1.26 

41.69 

Ferrous oxide (FeO). 

32.11 

32.02 

Manganous oxide (MnO). 

1.48 


Magnesia (MgO). 

Tr. 


Lime (CaO). 



Titanium dioxide (Ti0 2 ). 

16.34 

19.48 

Phosphorus pentoxide (P 2 0 5 ). . . . 

.43 


Chromium trioxide (CroCC) . 

Tr. 


Vanadium pentoxide (V2O5). 

. . . None 

99.72 



224 Nitze, H. B. C., Idem., p. 185. 

225 Unpublished report to Tennessee Geol. Survey. 

226 Keith, Arthur, U. S. Geol. Survey Geol. Atlas', Roan Mountain folio (No 151) Eco¬ 
nomic Geology map, 1907. 



























MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


223 


Assuming that all the ferrous iron which is not in magnetite is 
present in ilmenite, the percentages of magnetite, ilmenite, and rutile 
present in the specimens, as indicated by the analyses, are 69.60, 22.19, 
and 4.8 for the first specimen, and 60.55, 27.97, and 4.8 for the second 

Specimens of the ore collected by Hamilton are as a rule a compact, 
coarsely crystalline black mass with a purplish tinge, containing a few 
small white grains in ill-defined lines, parallel to the walls of the vein. 
In some places the ore has been mashed to a schistose aggregate in which 
spangles of a brassy-yellow mica coat the schistose planes. Under the 
microscope the white grains are seen to be crushed feldspars, a few of 
which exhibit twinning bars. A few flakes of mica occur in the feldspar 
and scattered sparsely through the ore mineral. Tiny, irregular par¬ 
ticles of rutile are also scattered through the ore mineral and in some 
portions of it the particles are arranged in lines. The proportion of 
rutile to the opaque ore minerals is very much smaller than in the case 
of the Ashe County ores (pages 209 to 216), and there is no suggestion 
that it has arisen through decomposition of ilmenite. 


Other deposits 

On the road between Shell Creek and Lunsford Branch Hamitlton 
reports the presence of several small deposits of magnetite, but states 
that exposures are insufficient to show whether they are of importance 
or not. Specimens picked from the surface of the “lands of Montgomery, 
Cordell and others” on Cordell Branch of Laurel Fork contain a com¬ 
paratively large quantity of titanium. One specimen yielded Dr. J. I. 
I). Hinds, of the Tennessee Geological Survey, the following result: 


Partial analysis of titaniferous magnetite from lands of Montgomery, Cordell and others, 

near Shell Creek, Carter County, Term. 


Silica (Si0 2 ). 15.20 

Alumina (AI 2 O 3 ). 11.96 

Iron (Fe). 37.40 


Lime (CaO). 5.20 

Phosphorus pentoxide (P 2 O 5 ). ... 7.30 

Titanium dioxide (Ti0 2 ). 8.00 


YANCEY COUNTY, N. C. 

So far as known titaniferous magnetites in Yancy county are spo¬ 
radic. In the western part 227 of the county near the head of Possom 
Trot Creek and 9 miles west of Burnsville magnetic float ore on the land 
of Jerry Ferguson contains 2.56 per cent of titanium dioxide (Ti0 2 ), 
and 39.00 per cent of iron (Fe). 

Six miles north of Burnsville, on the south side of Mine Fork, two 
openings 228 on the land of D. M. Hampton expose the same bed of ore 
6 to 10 feet across, with a nearly vertical dip. The magnetite is in “a 


227Nitze, H. B. C., Op. cit., p. 186. 
228idem., p. 187. 









2,21 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

gangue of chlorite, small pieces of quartz and feldspar, and a peculiar 
brown mineral with a high luster, possibly rutile or brookite.” Its 
analysis is given below. 

Partial analysis of titaniferous magnetite from neighborhood of Burnsville, X . C. 

S'ilica (Si0 2 ). 9.25 Phosphorus (P).Oil 

Iron (Fe). 39.42 Titanium dioxide (Ti0 2 ) . 11.90 

Sulphur (S).12 


MADISON COUNTY, N. C. 

On the eastern slope of New Found Mountain near the headwaters 
of Spring Creek on the land of Swan Woody, is a vein of ore 5 feet to 
6 feet wide, but the of nature tho rocks in which it occurs is not known. 229 
Its analysis gave: 

Partial analysis of ore from Spring Creek, Madison County, N. C. 

Silica (Si0 2 ). 2.37 Phosphorus (P).014 

Iron (Fe). 62.16 Titanium dioxide (Ti0 2 ). 7.44 

Sulphur (S).026 

On the waters of Paint Fork half a mile above its mouth, on the 
land of John Brigman, black, non-magnetic, highly lustrous float ore 230 
contains Ti0 2 in large quantities. 

One of the most notable occurrences of titaniferous ore in the State 
so far as its titanium content is concerned is on the headwaters of Ivy 
Creek near the public road between Asheville and Burnsville. Here 
according to Kerr and Hanna 231 is an ore in which there must be rutile. 
Unfortunately nothing is recorded of its associations. 


Analysis of titaniferous magnetite from headwaters of Ivy Creek, Madison County, N. C. 


Silica (Si0 2 ).83 

Alumina (A1 2 0 3 ). 9.51 

Ferric oxide (Fe 2 Os). 11.03 

Manganic oxide (Mn 2 0 3 ).89 

Ferrous oxide (FeO). 37.06 

Magnesia (MgO).93 

Lime (CaO). 2.57 

Sulphur (S).09 

Phosphorus (P). Tr. 

Titanium dioxide (Ti0 2 ). 37.88 

Water (H 2 0). .15 


100.94 

If all the FeO not required for magnetite is assumed to be in ilmenite 
there is an excess of this oxide amounting to 2.5 per cent., which must 

229 Nitze, H. B. C., Op. cit., p. 190. 

230 Idem., p. 189. 

231 Kerr, W. C.. and Hanna, G. B., Ores of North Carolina: Geol. of North Carolina 
vol. 2, chap. 2, p. 181, 1888. 


























MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


225 


occur as rutile. As, however, some of the iron is undoubtedly in silicates 
the sample probably contained a little more rutile than the calculation 
indicates. 


MACON COUNTY, N. C. 
Dobson Mountain 


Within a radius of 5 miles of Franklin are several deposits of titan- 
iferous ores that have been explored superficially, but of which little is 
known. The only ones concerning which any very definite descriptive 
statements are made, are said to be in a chloritic gangue. 

On the northeast slope of the divide between Cartoogajay and 
Skenah creeks, and 2 miles above the mouth of the former and 4 miles 
west of south from Franklin a rectangular pit 232 has exposed the top of 
a fine-grained magnetite mixed with a little garnet and considerable 
dolomite in a chloritic gangue. Its analysis shows: 


Partial analysis of emery ore from near Franklin, Macon County, N . C. 


Silica (Si0 2 ) . 11.91 

Iron (Fe). 20.64 

Manganese (Mn).69 

Sulphur (S).089 


Phosphorus (P).017 

Titanium dioxide (Ti0 2 ). 8. *20 

Calcium carbonate (CaC0 3 ). 3.31 


Magnesium carbonate (MgC0 3 ). .14.69 


In the presence of notable quantities of the carbonates this ore is 
like that on Warrior Creek and on the Curtis place in Caldwell county 
(page 228); but in neither case does Nitze refer to the carbonates or 
give any details that will explain their presence. 

Because of the small quantity of iron reported in this ore Mr. J. L. 
Stuckey of the North Carolina Geological and Economic Survey was 
asked to visit the locality and collect specimens of the ore and associated 
rocks. He found that the opening in question is on the northeast side of 
Dobson Mountain which is the divide between Cartoogajay and Skenah 
creeks. There are in the neighborhood several openings from which 
emery had been taken on the land of Alex. Waldroop on Potts Creek, 
about 2 miles above its mouth. Some time ago the place was pros¬ 
pected 233 by W. S. Lucas of Franklin, N. C., and some ore was taken 
away. Again, during the war, one large pit was opened and several tons 
of crude emery were sent to the mill to be concentrated. 

The country rock, according to Pratt, is a hornblende gneiss in 
which are lenses of a saprolitic amphibolite, which is thought to occur as 
dykes near the periphery of peridotite masses intrusive in the gneiss. 
The amphibolites on Dobson Mountain are in small, isolated lenticular 
bodies a few hundred feet wide and several times as long, with a trend 
which is approximately parallel to the strike of the gneisses by which 


lina: 


232 Nitze, H. B. C., Op. cit., p. 194. 

233 Pratt, J. H., and Lewis, J. V., Corundum and the peridotites of western North Caro- 
North Carolina Geol. Survey, vol. 1. p. 251, 1905. 











226 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

they are surrounded. The general strike of the lenses is the same as 
that of the gneiss, which is about N. 45° E., but they “are not in line 
with one another, but in a number of lines that are approximately pa¬ 
rallel.” The ore appears to be in a series of indefinite veins, the largest 
of which is 15 to 20 feet wide. “It occurs along a contact of a sort of 
talc or soapstone material. . . . Wherever the ore occurs there seems 
to be a well-defined body of this material alongside of it. . . . and in 
places small pieces of well-defined soapstone can be picked up.’’ 234 

The specimens collected to represent the rocks associated with the 
ores are light-gray talcose amphibolites which are, no doubt, altered 
phases of the peridotite of the district. The carbonates that are shown 
to be present by the analysis are secondary products developed during 
the alteration of the amphibolites to talc. The supposed ores are fine¬ 
grained grayish-black granular masses containing a few small mica 
flakes. Their thin sections show an aggregate of light-green amphibole, 
colorless corundum, with here and there splotches of a blue color, bright- 
green spinel, reddish-brown rutile and opaque magnetite. The magne¬ 
tite and rutile serve as the matrix by which the other minerals are sur¬ 
rounded. Magnetite and spinel are the most abundant components, 
followed by rutile, amphibole and corundum. The last named mineral, 
in the two slides studied, occurs in streaks through the aggregate and 
the rutile appears to crowd around the magnetite as though deposited 
upon it . 235 The ore is plainly a separation from the amphibolite phase 
of the peridotite magma. The occurrence is especially interesting 
because the ore is composed of the same mixture of magnetite, rutile, 
green spinel and corundum, that is found in many of the titaniferous 
ores, though, of course, in different proportions, and because the rock 
associated with the ore is a phase of peridotite and is like that associated 
with some of the titaniferous ores. 

Other Deposits 

: ; W 1 I J ’ 1 ^ 

A heavy float of a highly lustrous magnetite is on the land of Felix 
Kilpatrick 236 , 5 miles east of Franklin and one-eighth mile north of 
Culasagee Creek, in a gangue of chlorite and quartz. The country rock 
is mica schist. The strike of the vein is N. 35° E. Its analysis gave: 

Partial analysis of titaniferous magnetite near Franklin, Macon County, N. C. 

Silica (Si02).77 Phosphorus (P).014 

Iron (Fe). 54.24 Titanium dioxide (Ti02). 17.60 

Sulphur (S).04 

A similar ore 237 is found also on the land of Capt. T. M. Angel on 
the south side of the creek. 

234 Letter from Mr. J. L. Stuckey. 

245 The Fixkorper-Absatz of Vogt. See Jour, of Geo]., vol. 29, p. 319, 1921 

236 Nitze, H. B. C., Op. cit., p. 192. 

237 Idem., p. 193. 









MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 227 

On Ellijay Creek, 7 miles east of Franklin, what appears to a mag¬ 
netic pegmatite 238 outcrops in a large massive ledge, in the midst of 
mica and hornblende schists and gneisses, striking N. 40° W. It re¬ 
sembles somewhat the rock in the pit on Grassy Bald of Roan Mountain, 
but the character of the magnetite has not been determined. 

A few other titaniferous magnetites are reported to occur in the 
county but no evidence is given to show that they contain titanium. 


238 Idem., p. 193. 




CHAPTER XII. 


MINES AND PROSPECTS IN TITANIFEROUS 

MAGNETITES 

DEPOSITS IN THE PIEDMONT AREA, NORTH CAROLINA 

PRELIMINARY STATEMENT 

Titaniferous magnetites are known to be present in the western 
portion of the Piedmont Plateau but none of the deposits have been seen 
by the writer. For our information concerning them we are dependent 
upon the descriptions of Nitze and of Singewald. They are described 
again in this place because they have been studied in more detail than 
the similar deposits in the mountain district and because the results of 
their study throw considerable light on the character and origin of the 
mountain deposits. 


CALDWELL COUNTY, N. C. 

Farthing place 

At the Farthing place on Warrior Creek, miles north of Lenoir, 
a sample 23 9 of ore picked from the surface is like that analyzed from 
Cartoogajay Creek (page 225). The occurrence is described by Singe¬ 
wald 240 as an outcrop of compact, fine-grained magnetite in a gangue of 
green hornblende schist intercalated with more acid schistose rocks. 
The ore is disseminated through the schist in minute grains and in 
stringers of nearly pure ore. No openings are known to have been 
on the deposit. Singewald writes: 

“Locally this hornblende rock contains richer portions of fine-grained ore. A 
thin section of such a piece consisted principally of the ore minerals and spinel. Less 
abundant were augite and hornblende. The ore grains are less than 0.5 millimeter 
in diameter, and do not constitute more than one-third of the mass. On etching pol¬ 
ished surfaces of these ores, the small magnetite grains are dissolved out without show¬ 
ing any ilmenite intergrowths, and the polished surfaces of the ilmenite femain un¬ 
attacked. ” 


Partial analysis of ore from Farthing place, Caldwell County, N. C. 


Silica (Si0 2 ). 6.50 

Aluminum (Al). 18.47 

Iron (Fe). 31.92 

Manganese (Mn).39 

Sulphur (S).058 

Phosphorus (P).025 


Titanium dioxide (TiOo). 2.40 

Phophorus ratio (P:Fe).078 

Calcium carbonate (CaC0 3 ). 7.48 


Magnesium carbonate (MgCOj). .15.64 


239 Nitze, H. B. C., Op. cit., p. 119. 

240 Singewald, Jos. T., Jr., U. S. Bur. Mines Bull. 64, p. 85, 1913. 












MINES AND PROSPECTS IN TITANIFEROUS MAG/NETITES 229 

Richlands Cove 

Another deposit uncovered by a pit on Joshua Curtis s farm in 
Richland s Cove- 41 in the east bank of the Yadkin River, 16 miles north 
Lenoir, is a compact, lustrous, slightly magnetic ore in an ore-body 
45 feet thick distributed through a taleose-chlorite schist. The analysis 
of an average sample is quoted in column 1. “Occasionally, harder 
and very much purer streaks of ore occur.” Samples of these show a very 
much larger content of Ti0 2 (column 3). Sample 2 was selected from 
what appeared to be the purest ore. 


Partial analyses of ore from Richlands Cove, Caldwell County, N. C. 



1 

2 

3 

Silica (Si0 2 ). ... .... 

6.63 

7.55 


Iron (Fe). 

36.00 

28.24 

37.10 

Manganese (Mn). 

1.09 



Sulphur (S). 

.021 

.013 


Phosphorus (P) . 

.060 

. 140 

Tr. 

Titanium dioxide (TiO->).... 

15.00 

41.21 

36.40 

Calcium carbonate (CaC0 3 ). . 

7.37 


• • • • 

Magnesium carb’ate (MgC0 3 ) 

16.08 

_ 

. . . . 


Concerning the Richland’s Cove deposit Singewald 242 writes: 

A small opening has been made adjacent to the river bank exposing a face about 
20 feet high and 40 feet wide. This titaniferous mass occurs within a country rock 
consisting of sericitic schist It consists of small particles of ore in a matrix chiefly 
made up of fibrous and scaly aggregates of chlorite, serpentine, and talc. The indivi¬ 
dual ore particles average less than one-half millimeter in diameter, and rarely exceed 
1 millimeter. They are very slightly magnetic to nonmagnetic. Two polished sec¬ 
tions of the ore etched with hydrochloric acid retained their luster and showed no 
evidence of the intergrowths of ilmenite and magnetite. These facts, together with 
the high titanium content shown in the analyses in the table . . ., indicate that the 
ore particles consist chiefly of ilmenite. This is further borne out by the fact that 
the sands along the river close to the deposits contain only nonmagnetic ore particles.” 


Here again (compare page 228) are found in the ore large quantities 
of calcium and magnesium carbonates and no explanation of their 
presence in the description of either of the two geologists who have seen 
the occurrence. The descriptions strongly suggest an ore like that on 
Dobson Mountain (page 225). 

Float ore of the same kind has been traced half a mile northeast 
and a quarter of a mile southwest of the cove. 


241 Nitze, H. B. C., Op. cit., p. 120. 
242 Op. cit., p. 84. 









230 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 



Figure 22. Map of the northern portion of iron ore-belt of Rockingham and Guil¬ 
ford counties. North Carolina, showing location of Shaw mine. (After J. P. Lesley.) 

ROCKINGHAM, GUILFORD AND DAVISON COUNTIES, N. C. 

TUSCARORA AND SHAW BELTS 

The most important zone 243 of titaniferous magnetites in North Caro¬ 
lina extends from the headwaters of Abbots Creek in Davidson County, 


2 < *3Kerr, W. C., Report of the Geol. Survey of North Carolina, vol. 1, pp. 236-250, 1875. 
Kerr, W. C., and Hanna, G. B., Ores of North Carolina: Geol. of North Carolina, 
vol. 2, chap. 2, pp. 143-154, 1888. 

Willis, Bailey, 10th Census U. S., vol. 15, p. 308, 1886. 

Nitze, H. B. C., Op. cit., pp. 60-68. 















MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


231 



Figure 23. Map of southern portion of iron-ore belt in Rockingham and Guilford 
counties. North Carolina, showing position of Tuscarora mine. (After J. P. Lesley.) 

northeastward across the southwestern corner of Forsyth County and 
entirely across Guilford County to Haw River in Rockingham County, 
a distance of 30 miles. (Figures 22 and 23.) It consists of two parallel 
belts 3 miles apart throughout their greatest distance but approaching 
toward the northeast until they are believed to unite in Rockingham 
County. The ore is described as a granular magnetite mixed with 










232 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


P 



o 




ScaJ-e 

■too 




/ SJuift 
3 O' deep. 

Figure 24. Openings at the Tuscarora Iron Works, Guilford County, North Carolina. 
(After Bailey Willis.) 

menaccanite, probably also with rutile and a chloritic mineral, or a 
silvery micaceous one resulting from its decomposition. The ore bodies 
consist of strings of lens-shaped masses, continually enlarging and con¬ 
tracting in thickness, from a few inches to 6 or 8 feet. Some of the ores 
contain granular corundum, in one or two places in such quantities that 
they become true emery. Lesley thought that the ore-bearing layers 
were deposited at the same time as the rocks that hold them, since they 
differ from the other rocks of the series only in that they are more 
















MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


233 



't's 


0 Store Hovlsi 



Figure 25. Plan and sections at Dannemora mine, Rockingham County, North 
Carolina. (After Bailey Willis.) 


highly charged with iron. (See page 26.) The ore beds vary in num¬ 
ber at different places and are irregular in position in the non-ferriferous 
rocks, but Singewald 244 , who visited the Guilford county occurrences in 
connection with his work on the utilization of the titaniferous magne¬ 
tites, found that the ore-bodies are segregations within small gabbro 

244 Singewald, Jos. T., Jr., The titaniferous iron ores in the United States: U. S. Bureau 
of Mines Bull. 64, p. 86, 1913. 


























234 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

masses that have “a linear distribution along the belt.” They do not 
constitute a continuous body extending the entire length of the belt, 
and consequently the ores are not continuous. At the Tuscarora mine 
the rock immediately associated with the ore is an olivine gabbro with 
a disabasic texture and the gangue of the ore a mass of chlorite and a 
small quantity of material so decomposed as to make it undeterminable. 

Tuscarora and Dannemora mines 

The Tuscarora mine was the most important opening on the south¬ 
eastern belt. (See Figure 23.) It was situated 1 mile north of Friend¬ 
ship in Guilford County. It was examined in 1871 by J. P. Lesley and 
as the result of his work it was operated for local forges. The ore was 
traced for a mile in a direction N. 77° E. (See Figure 24.) A shaft 
was sunk to 109 feet cut two beds of ore of which one was 12 feet thick. 
Their dip is about 70° a little east of south, but is said to change to 
northwest at a greater depth. 245 

The Dannemora mine was in Rockingham County 20 miles north¬ 
east of the Tuscarora mine on the same belt. It was in operation in 
1880 when it was visited by Bailey Willis, who reported the ore deposit 
to be 125 feet long, 80 feet wide on the incline used, and 12 feet thick. 
(Figure 25.) Other lenses of approximately the same size were later 
found to the northeast and the southwest of the main one. The ore 
was accompanied by chlorite and mica. 

Analyses of samples taken from various points on this belt are given 
as follows: 


Ayialyses of ores from deposits on Tuscarora belt. 



1 

2 

3 

4 

5 

6 

7 

8 

Silica (Si(L). 

1.31 

4.70 

.76 

.40 

1.30 

12.75 

1.30 

26.80 

Iron (Fe). 


48.31 

57.68 

59.03 

56.41 

41.95 

67.60 

21.63 

Alumina (AL0 3 ). 

. . 4.26 

8.66 

1.68 

1.06 

2.54 

5.17 

.55 

8.87 

Magnesia (MgO). 

2.33 

2.96 

2.79 

1.99 

2.41 

4.14 

.75 

10.30 

Lime (CaO). 

.60 

1.42 

.45 

.24 

.51 

.90 

.14 

1.40 

Sulphur (S). 

Tr. 

.089 


... 

.... 

• • • • 

.... 


Phosphorus (P) . 

Tr. 

.023 

.... 

. . . 

.... 

.... 

.... 

. .. . 

Titanium dioxide (Ti(L). . . . 

. . 13.60 

13.71 

13.52 

11.95 

12.35 

15.35 

1.25 

16.20 

Chromic oxide (Cr 2 0 3 ) . 

.72 

.34 

.46 

1.07 

1.10 

1.25 

1.43 

.43 

Manganese oxide (MnO) . . . 
Cobalt oxide (CoO). 

.96 

.11 

.81 

1.02 

1.10 

1.25 

.93 

1.55 

Water (H 2 0). 

.18 

.96 

• . . . 

.38 

.79 

1.36 


3.55 


1. Sargent shaft, Tuscarora mine, Guilford County. The iron was reported as Fe 3 C> 4 , 
76.04 per cent. (F. A. Genth: Geol. of North Carolina, vol. 1 , p. 245, 1875.) 

2 . Dannemora mine. Rockingham County. (From analysis reported in 10 th Census 
U. S., vol. 15, p. 311, 1886.) 

3. Iv. R. Swain’s, Davidson County. Iron is reported as Fe 3 0 4 , 79.53 per cent by 
Genth. (Kerr, W. C., Geol. of North Carolina, vol. 1 , p. 245, 1875.) 

4. Granular ore, Elisha Charles, Guilford County. Iron reported as Fe 3 0 4 , 81.89 
per cent. (Idem.) 

5. John Clark, Guilford County. Iron reported as FesO 4 , 77.90 per cent. (Idem.) 

6 . Soft micaceous ore, Mrs. McCuiston, Guilford County. Iron reported as Fe 3 0 4 
57.93 per cent. (Idem.) 

7. Magnetic portion of 6 . Iron reported as Fe 3 0 4 , 93.63 per cent. (Idem) 

8 . Non-magnetic portion of 6 . Iron reported as Fe 3 C> 4 , 30.90 per cent. (Idem.) 


245Willis, Bailey, 10 th Census, U. S., vol. 15, pp. 308-311. 















MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


235 


From a comparison of anlvses 6, 7 and 8, it will be seen that as early 

as 1875 it was learned that the titanium could be nearly eliminated 

«/ 

from this ore by careful magnetic cobbing. In 1914 Singewald 24 6 re¬ 
peated the experiment more carefully, using Tusearora ore, and reached 
a result which was not quite so satisfactory. His figures are: 


Result of magnetic treatment of Tusearora titanif erous magnetite. 


Composition 

Yield in Titanium 

concentrate Iron dioxide 

Per cent. Per cent. Per cent 

_ Ore . 58.07 12.82 

71.5 Concentrate, ore crushed to 0.3 mm. G7.76 4.25 

.... Tailings, do. 33.76 34.32 

70.1 Concentrate, ore crushed to 0.15 mm. 68.41 3.64 


A complete analysis 247 of the Dannemora ore is quoted below: 

Complete analyses of titanif erous magnetite from Dannemora mine, Guilford County, 

North Carolina. 


Whole Insoluble 

ore portion 

Silica (Si0 2 ). 4.70 4.70 

Alumina (A1>0 3 ). 8.66 9.75 

Ferric oxide (FeoCL). 43.05 .... 

Chromic oxide (CT 2 O 3 ) . .34 .... 

Ferrous oxide (FeO) . 23.51 .... 

Manganese oxide (MnO) . .15 .... 

Magnesia (MgO). 2.96 .72 

Lime (CaO). 1.42 .56 

Pyrite (FeS 2 ).133 

Nickel sulphide (NiS). .01 .... 

Cobalt sulphide (CoS). 03 .... 

Copper sulphide (CuS). .01 .... 

Soda (Na 2 0).05 .05 

Potash (K 2 0). -03 .03 

Carbon dioxide (C0 2 ). .07 .... 

Phosphorus pentoxide (P 2 O 5 ). .052 .045 

Titanium dioxide (Ti0 2 ). 13.71 11.82 

Carbon in carbonaceous matter. .06 .... 

Water at 110 ° (H 2 0). .21 .... 

Water above 110 ° (H 2 0) . 06 .... 


Total. 100.00 


Insoluble siliceous matter. 28.00 27.675 

Iron (Fe) . 48.31 

Sulphur (S). • 089 

Phosphorus (P) . • 023 

Phosphorus ratio (P:Fe). .048 


A significant feature of this analysis is the presence of 11.82 per 
cent of TiQ 2 and no iron in the insoluble portion of the sample, indicat- 


2460p. cit., p. 22. 

smoth Census U. S., vol. 15, p. 311. 







































236 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

ing the existence of rutile, and the presence of 9.75 per cent A1 2 0 3 
without sufficient MgO to combine with all of it to make spinel, indicat¬ 
ing the existence of corundum. If all the Ti0 2 shown in the soluble 
portion of the whole ore is present in the form of ilmenite there cannot 
be more than 3.65 per cent, of this mineral present. No thin sections 
of the Dannemora ore have been studied but those of the similar Tus- 
carora ore show the presence of spinel and rutile, and corundum is known 
to exist in the extension of the same line of ore-bodies farther north¬ 
east. (See page 232.) 

No complete analyses of the Tuscarora are available, except one 
made by Genth, and published in 1875 (see page 234), and this did not 
distinguish between ferrous and ferric iron and consequently cannot 
be used to calculate the proportion of ilmenite and rutile present in 
the ore. Singewald 248 , however, has given us pictures of two polished 
and etched surfaces of the Tuscarora ore. He states: 

“Ilmenite grains make up one-fifth to two-fifths of the surface; and they range 
in size from 2 millimeters to 0.2 millimeter, though very few fall below 0.5 millimeter 
in diameter. The most striking feature of the ore is the ilmenite intergrowths in the 
magnetite, which attain a coarseness not approached in any of the other ores that have 
been studied. Indeed, so coarse are they as to be easily discernible with the naked 
eye. . . . The individual ilmenite plates have an average length of 2 millimeters, 
but some attain a length of as much as 4 millimeters. The space between the parallel 
plates varies from 0.2 to 0.5 millimeters, and the plates themselves may be as thick as 
0.1 millimeter. Another characteristic feature is protuberances or local thickenings 
of the plates. This most frequently takes place at one end, the other end thinning 
out, giving an elongated, wedge-shaped appearance. These plates are plainly visible 
on cleavage faces of magnetites on the unpolished surfaces of pieces that have been 
etched, and are frequently coarse enough to peel off with the edge of a knife blade.” 

Specimens of the ore collected by Mr. Stuckey are fine granular 
aggregates of magnetite, a brownish yellow decomposition product of 
some silicate, and a few colorless transparent grains. A layer of talcose 
plates coats the w'alls of joint cracks and little bunches of talc or some 
similar mineral are scattered through the ore mass. Much of the mag¬ 
netite is crystallized in little octahedrons. 

Four thin sections of the Tuscarora ore, made from two specimens 
kindly furnished by Dr. Singewald, show the presence of many grains 
of red-brown rutile, a small quantity of a green transparent isotropic 
mineral that is probably pleonaste or a spinel closely allied to this, 
much opaque material and a very little colorless or very light-green 
amphibole that may be anthophyllite. The opaque material is mainly 
magnetite with perhaps some ilmenite, but the two cannot be discrim¬ 
inated. The rutile occurs embedded in the ore mineral and also to a 
less extent in the interstitial amphibole. Its particles bear the same 
relation to the magnetite as do the light and dark minerals shown in 


248 Op. cit., pi. II. C. and pi. VII. A. and p. 88. 




MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


237 


Singewald’s photograph 24 9 of a polished specimen of the ore. The rutile 
in the ore occupies the position corresponding to the light portions of 
the photograph. It usually occurs in streaks about 1 millimeter long 
and about 0.12 millimeter wide, or in sharp-edged rhomboidal or wedge- 
shape grains measuring about 0.7 by 0.3 millimeter in diameters, but 
it occurs also as very irregularly outlined pieces, as narrow rods and as 
little dust-like particles scattered irregularly through the magnetite. 
It is reddish-brown, fairly strongly pleochroic in yellowish and brown 
tints and is clouded toward the center with reddish opaque substances 
that suggest red stained leucoxene, or perhaps limonite. In several 
instances in the centers of the rutile are little masses of a green spinel 
with very irregular shapes. 

The Tuscarora ore resembles very closely the titaniferous ore in the 
Mountain district and is, at the same time, similar to the emery ore on 
Dobson Mountain (page 225). It differs from the Dobson Mountain 
ore mainly in the proportions of the components present. It is true 
that no corundum was detected in the thin sections of the Tuscarora 
ore, but the mineral is known to be present in some portions of the ore 
mass. 


Shaw mine 

On the Shaw belt which is 3 miles northwest of that on which the 
Tuscarora and Dannemora mines are situated, 3 or 4 distinct and parallel 
deposits were opened, the widest of which measured 6 feet in width 
where solid. Some pits on the property were worked in Revolutionary 
times, but the main openings were made in the seventies. 

Analyses 250 of a fine-grained, black, slightly micaceous ore from the 
Shaw mine (column 1) and of a sample from the Hopkins farm (column 
2) adjoining the Shaw mine on the northeast follow: 

Analyses of titaniferous magnetite from the Shaiv belt in Rockingham County , N. C. 

1 2 


Silica (Si0 2 ). 

. 1 

80 


74 

Magnetite (Fe 3 04 ). 

. 74. 

81 

76. 

80 

Manganese oxide (MnO) .... 
Cobalt oxide (CoO). 

. 1 1 . 

53 

1 

30 

Alumina (A1 2 0 3 ). 

. 2. 

66 

3. 

82 

Magnesia (MgO). 

. 3 

.09 

1 

.80 

Lime (CaO). 


.69 


. 55 

Titanium dioxide (Ti0 2 ). 

. 14 

.46 

13 

. 92 

Chromic oxide (Cr 2 0 3 ) . 


.97 

1 

.07 


100 

.01 

100 

.00 


2490p. cit., pi. II. C. 

2soKerr and Hanna, Op. cit., p. 150. 














238 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


Apple plantation 

One other occurrence in Rockingham County is of special interest. 
It was first described by Genth 251 and later was referred to by Kerr 
and Hanna 252 . Pratt and Lewis 253 identify the locality as being in Guil¬ 
ford County, 7 miles northeast of Friendship, but Singewald 254 thinks it 
was on the old Apple plantation, southeast of the Haw River, just across 
the line in Rockingham County, for on the surface at this place are 
fragments of gray and pink emery. 

No description of the association of the ore is given but two samples 
were described and analyzed by Genth. One was a granular, reddish 
ore resembling a reddish-brown garnet and the other a grayish granular 
ore in which are minute grains of corundum which have a yellowish 
or brownish white color, and show in many places cleavage fractures, 
which give it the appearance of a feldspathic mineral. 

Genth’s analyses showed: 


Analyses of ore from Apple plantation, Rockingham County, N. C. 


Silica (Si0 2 ). 

Magnetite (FesCL). 

Alumina (ALO3). 

Manganese oxide (MnO) . 

Cobalt oxide (CoO). 

Magnesia (MgO). 

Lime (CaO). 

Titanium dioxide (Ti0 2 ). . 
Chromic oxide (Cr 2 0 3 ) . . . 


Reddish ore 

Gray ore 

1.39 

.98 

42.77 

46.29 

52.24 

44.86 

1.00 

1.27 

.68 

3.27 

00 

.91 

.78 

2.42 

.30 

Tr. 


100.00 100.00 


There is no definite statement in any of the descriptions that this 
ore is associated directly with basic rocks but the presence in it of corun¬ 
dum in such large quantity suggests that it might well be genetically 
related to the corundum-bearing peridotites that have been so carefully 
studied by Pratt and Lewis. (Compare description of Dobson Mountain 
occurrence, page 225). 


DAVIE COUNTY, N. C. 


Titaniferous magnetites occur on the Maxwell place in Davie 
county about 5 miles south of Mocksville near the mouth of Bear Creek 
where float shows a medium-grained magnetite very free from gangue.* 55 
The country rock is “hornblende and syenite” with occasional dissemina- 


251 Kerr, W. C., Rept. of the Geol. Survey of North Carolina, vol. 1, pp. 245-246 1875 
252 Iverr, W. C., and Hanna, Geo. B., Ores of North Carolina: Geol. of North Carolna’ 
vol. 2, chap. 2, pp. 150-151. 

253 Pratt, J. H., and Lewis, J. V., Corundum and the peridotites of western North Caro- 
ina: North Carolina Geol. Survey, vol. 1, p. 263, 1905. 

254 Op. cit., p. 90. 

J55 Nitze, H. B. C., Op. cit., p. 84. 














MINES AND PROSPECTS IN TITANIFEROUS MAGNETITES 


239 


tions of magnetite granules. Surface specimens contain 60.00 per cent 
of iron, 0.033 per cent of sulphur, 0.008 per cent of phosphorus, and 
10.32 per cent of titanium dioxide. Float can be traced for lj^ miles 
southwest to South Yadkin River. 

Ten to 12 miles northeast other float ore and pits indicate the 
presence of a 15-foot vein at the summit of a hill on the farm of J. A. 
Allen. 256 The vein is in a hornblende country rock slightly impregnated 
with magnetic granules. The ore, which was worked during the Civil 
War at a forge on Dutchman’s Creek, contains 52.80 per cent of iron, 
0.11 per cent of sulphur, 0.02 per cent of phosphorus, and 8.00 per 
cent of titanium dioxide. 


256 Nitze, H. B. C., Op. cit., p. 85. 



CHAPTER XIII. 


HEMATITIC MAGNETITES 

DEPOSITS IN NORTH CAROLINA 

At several localities in North Carolina and in Carter County, 
Tenn., are deposits of iron-ore that consist of mixtures of magnetite and 
hematite in widely different porportions. In some instances the mix¬ 
tures are so nearly pure hematite that they are only weakly attracted 
by a small magnet. In other cases the magnet attracts them nearly 
as strongly as it does the more common magnetites. As most of the 
deposits are small, they have not attracted much attention from pros¬ 
pectors. 

Nitze 257 has referred to several deposits of this kind in Watauga 
County, N. C., and several others near the boundary between Mitchell 
County, N. C., and Unicoi County, Tenn., but gives no description of 
their manner of occurrence. He also mentions the fact that the W au- 
tauga County belt probably extends into Carter County, Tenn. Martite 
schists have been described 258 from the neighborhood of Boone and near 
the crest of the Blue Ridge as far northeast as the Virginia line. Two 
analyses of these ores by Hanna are given below: 

Analyses of ore from martite schists in Caldwell and Wautauga counties, N. C. 

Richlands Bull Ruff in 
Cove ore bed 


Silica (Si0 2 ). 

2.2 5 

2.617 

Alumina (AI2O3). 

.87 


Ferric oxide (Fe^C^). 

96.14 

92.916 

Ferrous oxide (FeO) . 


2.448 

Manganese oxide (MnC) . 

Tr. 

.450 

Iron sulphide (FeS<>). 

.08 

.048 

Sulphur trioxide (SO3). 

.01 


Phosphorus pentoxide (P 2 Ot). 

.00 

Tr. 

Titanium dioxide (Ti0 2 ). 

Water (H 2 0). 

.85 

Tr. 


100.20 98.479 

The only specimen from any of the occurrences in this belt that 
was seen by the writer shows a network of hematite veins forming a 2-inch 
wide zone in a white, fine-grained rock resembling, in general appear¬ 
ance, a crushed rhyolite, like the rhyolites associated with the ore at 
the Finney and Teegarden mines near Lunsford Branch. (See page 250). 

According to Nitze’s account a deposit of red specular hematite 
was uncovered in several small openings on Bald Mountain near the 


25TOp. cit., pp. 164-168. 

258Kerr, W. C., and Hanna, G. B., Ores of North Carolina: Geology of North Carolina, 
vol. 2, chap. 2, pp. 175-176, Raleigh, 1888. 


















HEMATITIC MAGNETITES 


241 


lieadwaters of Spring Creek in Mitchell County. The ore is said to be 

fine-grained and compact, and its walls to be “an arenaceous slate 

striking N. 25° E." Nothing is known of the size of the deposit, but 

it is stated that the belt of ore has been traced southwesterly for 7 miles 

«/ 

to Toe River. 


DEPOSITS IN TENNESSEE AND ADJACENT PORTIONS OF 
WATAUGA COUNTY, NORTH CAROLINA. 

The most important ores of this type occur near the north border 
of the area in Watauga and Carter counties that is indicated by Keith 259 
on the maps of the Cranberry and Roan Mountain cpiadrangles as un¬ 
derlain by Beech granite. Some of the deposits are in the Beech granite 
and others in the Cranberry granite which adjoins it. The Beech 
granite is characterized by Keith 2 6 0 as a white or pink porphyritic biotite 
granite that is intrusive in the Cranberry granite. It is regarded as 
the youngest of the Archean rocks of the district, but like all the other 
rocks of this age has been so metamorphosed that it has now become 
markedly schistose. 

«j 

A short belt of the hematitic magnetite ores has been reported by 
Nitze on the south side of Beech Mountain in the valley of Elk Creek 
where it appears as a “bed” between “slaty, gneissoid walls." It is very 
siliceous, strikes east-west and dips north. It is believed to be of no 
commerical value. 

DEPOSITS IN THE VALLEY OF LAUREL CREEK 


Whitehead prospect 


In the valley of Laurel Creek about 5 miles a little south of east of 
Hampton, on the crest of Keystone Ridge in Carter County, Tenn., is 
the Whitehead prospect in Cranberry granite. This exposed 4 feet of 
flinty hematite between a wall of the usual granite and one of a red, 
flinty granite in which there is visible only red feldspar and a mixture 
of magnetite and hematite or martite. Other specimens from this 
prospect are extremely fine-grained, homogeneous, steely or flinty, 
blue-gray hematites. The analysis of one of these made by Mr. Farrar 
of the Tennessee Geological Survey gave: silica (Si0 2 ), 14.86 per cent, 
ferrous oxide (FeO), 1.40 per cent, and ferric oxide (Fe 2 0 3 ), 82.84 
per cent. 

School House prospect 


About 6 miles farther east and a little south of the Whitehead 
place is the “School House" prospect where a very little work has shown 
an ore composed of magnetite and martite crystals and a little inter- 


zssKeith, Arthur, U. S. Geol. Survey Geol. Atlas, Cranberry folio (No. 90), 1903, and 
R ° an 2 6oi<Cejth a Arthur, ILS. Geol. Survey Geol. Atlas, Cranberry folio (No. 90), p. 3, 1903. 



242 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

stitial quartz. This ore, according to Hamilton 261 , from whose notes 
many of the descriptions of the hematitic magnetite ores are taken, 
is associated with a dark rock resembling a diorite. A sample of this 
analyzed by Dr. J. I. D. Hinds of the Tennessee Survey yielded 62.72 
per cent of iron, 9.10 per cent of silica (Si0 2 ), 0.60 per cent of alumina 
(A1 2 0 3 ), and no phosphorus or titanium. The greater part of the ore 
is magnetite. 

DEPOSITS IN WALNUT AND BEECH MOUNTAINS 

Big Ridge openings 

The most extensive explorations in this general area were made in 
its northern portion on the east and south slopes of Walnut Mountain 
and on Big Ridge, a northern spur of Beech Mountain, about 2 miles 
southeast of the mouth of Beech Creek. 262 

The ore at Big Ridge is a “partially magnetic specular hematite” 
in a “slate and hornblende gneiss." It occurs as a bed lj^ to 4 feet 
thick, made up of many streaks from one-half inch to 1 inch thick. It 
has a variable strike between west and northwest and a dip of 45°—90° 
N. or NE. 

Explorations near Elk Mills 

On the northeast slope of Walnut Mountain, (Map, Figure 26) 
from 2 to 3 miles east of Elk Mills, are several openings representing 
what were once extensive explorations. Since their abandonment they 
have become so filled with wash that they are now nearly obliterated. 
On Mays Ridge the ore is reported by Nitze to be “of considerable 
thickness” and to be of good quality. Four analyses made by J. C. 
Guild of Chattanooga are quoted by Nitze as showing the following 
ranges: silica (Si0 2 ) between 7.1o and 16.93 per cent, iron (Fe) between 
48.82 and 63.63 per cent, and phosphorus (P) between 0.006 and 0.054 
per cent. 

The other explorations in this vicinity uncovered similar ore. At 
Rabbit Station the ore appears in a low-dipping bed striking about 
east-west. Above and below it are thin layers of schist and beyond 
the schists is the prevailing gneiss of the region, which is mapped by 
Keith as Cranberry granite. The schist selvage is a thoroughly crushed 
granite in which all the feldspar has been changed to an aggregate of 
micaceous and uralitic alteration products in which small garnets have 
been developed and through which are streaks of epidote. At the Black 
Bear prospect, on the ridge west of Rabbit Station, the ore is a granular 
mixture of magnetite, a little hematite, quartz and feldspar. The one 


^‘Hamilton, S. H., Unpublished report to the Tennessee Geol. Survey 
2<s j Nitze, H. B. C., Op. cit., pp. 165-166. 





HEMATITIC MAGNETITES 


243 


specimen seen resembles in appearance a magnetitic pegmatite in which 
some of the magnetite has passed over into martite. 

None of the openings in this part of Walnut Mountain indicate 
deposits of economic importance or afford data for determining the origin 
of the ores. The meager descriptions of the occurrences suggest that 
the oies and their associations at these places are like those of the Luns¬ 
ford Branch occurrences described beyond, and that, in all likelihood, 
the method of origin at both places is the same. 



PALEOZOIC 

_A_ 


ALGONKIAN 


ARCHEAN 





b: 



Undifferentiated Linville metadiabase Cranberry granite Beech granite 

Nontitaniferoua magnetite ore ■ Titaniferous magnetite ore • Magnetite-hematite ore 


Fault 

Figure 26. Map showing location of prospects on Walnut Mountain, between Shell 
Creek and Butler, Tenn., and in adjacent portions of North Carolina. (Partly after A. 
Keith and S. H. Hamilton.) 1. Montgomery and Cordell explorations; 2. School House 
prospect; 3. Keystone Ridge or Whitehead prospect; 4. Miller prospect; 5. Dr. Smith ex¬ 
ploration; 6. Finney and Teegarden mine; 7. Lunsford prospect; 8. G. W. Stout exploration; 
9. May’s Ridge exploration; 10. Rabbit Station; 11. Black Bear prospect; 12. Black’s pros¬ 
pect; 13. Big Ridge exploration. 












































244 MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 

DEPOSITS ON LUNSFORD BRANCH 
Scrawl Ridge openings 

Lunsford Branch flows down the east slope of Walnut Mountain. 
At several points in its valley ore-deposits are known to occur, more 
particularly on the south side. Some of these have been explored by 
trenches and pits and at two or three places the Virginia Iron & Coke 
Co. made large open cuts, drove tunnels and sank a few shafts, in the 
hope of finding sufficient ore to warrant mining operations. The result 
was disappointing and the work was soon abandoned. 

The westernmost openings in this series are at the Miller explora¬ 
tion on Scrawl Ridge of Walnut Mountain, about three-quarters of a 
mile up the valley of Scrawl Branch, a tributary of Lunsford Branch. 
The country rock, which is mapped as Cranberry granite, is a crushed 
quartz, syenite, composed of about 20.7 per cent of quartz, 47.1 per 
cent of orthoclase, 9.8 per cent of albite, 3.9 per cent of anorthite, 
17.2 per cent of hornblende and 1.3 per cent of apatite. With this are 
masses of crushed dioritic rocks which in some places contain large 
quantities of magnetite in irregular grains and crystal particles grouped 
between hornblende grains as though introduced after the rock had 
suffered much crushing. As some of the larger grains are fractured, 
it is evident that the introduction was accomplished before the deforma¬ 
tion processes had ceased. Farther up the hollow the Virginia Iron, 
Coal & Coke Co. undertook a few other explorations and found a min¬ 
eralized zone of crushed diorite charged with magnetite and cut by vein- 
lets of epidote and quartz. 263 The descriptions suggest occurrences like 
that of the ore at Cranberry, except that the deposits are probably 
comparatively lean. They are unlike other deposits in this district 
and are more properly to be classed with the magnetites. 

Lunsford prospect 

The best known openings in the valley of Lunsford Branch are the 
Finney and Teegarden mine and the Lunsford prospect. The latter is 
a tunnel about miles east of the mouth of Scrawl Hollow, between 
Lunsford Branch and the road on its north side. The tunnel is reported 
to have entered the hill about 50 feet and to have cut good ore like that 
at the Finney and Teegarden mine. Nothing of interest can now be 
seen at the prospect except a little ore dump, on which the fragments 
are of a slightly banded, granular mixture of magnetite, perhaps a little 
martite, a very little pyrite and many little round particles of quartz. 
Their structure is that of a crushed rock into which iron oxides have been 
forced. According to Keith's mapping the prospect is in Cranberry 
granite, but a section on the road just above the tunnel shows a series 


263 From notes of S. H. Hamilton, unpublished report to Tennessee Geol. Survey. 



HEMATITIC MAGNETITES 


245 


of parallel layers of much crushed quartz syenite, fine-grained gray 
rocks and crushed dioritic rocks. The fine-grained rocks resemble 
granulitized felsites. Scattered through them, here and there, are 
particles of quartz and feldspar a trifle larger than the grains of the 
matrix in which they lie. This matrix is an extremely fine-grained 
aggregate of quartz, plagioclase and othoelase, tiny flakes of green 
hornblende and biotite, granules of epidote and wisps of muscovite. 
The constituent grains are elongate in a parallel direction and are often 
flattened. The whole mass is silicified so that original structures are 
unrecognizable. In the coarser veins of these rocks the fragmental 
character of most of the larger components is pronouced. Some of 
them, however, are crushed into shreds, and the rocks are distinctly 
schistose. The groundmass of all phases is, however, so fine-grained 
and its constituents are so thoroughly crushed that it is impossible to 
decide whether the rocks are crushed rhyolites or crushed granites or 
quartz syenites. 


Finney and Teegarden mine 

The Finney and Teegarden mine is between the Miller and the 
Lunsford prospects, about one mile west of the latter on the south side 
of the main stream of Lunsford Branch. In 1912 two upen cuts were 
made by the Virginia Iron, Coal & Coke Co., a tunnel was driven into 
the hill from the western cut, and a vertical drill hole was put down at 
the mouth of the tunnel. 

The country rock is a quartz syenite like that at the Miller and 
Lunsford prospect, but very much more thoroughly crushed and there¬ 
fore more schistose. Interlavered with this is a series of light-gray or 
white, massive and slaty rocks, chlorite schists, and black magnetic ore, 


c 



APPROXIMATE SCALE 

50 0 50 I00PEET 

■ iii j.j-i.i i i i- ' ■■ ■ J 

Figure 27. Diagrammatic cross section through Finney and Teegarden prospect, 
valley of Lunsford Branch, Carter County, Tennessee. (After S. H. Hamilton.) 








246 MAGNETIC IRON ORES OF EAST TENN. AND WP^STERN N. C. 

dipping south into the hill at about 35°. (See Figure 27.) dhe chlorite 
schist is in comparatively narrow layers bordering the ore, the two ap¬ 
parently grading. The two ore layers uncovered are about 5 feet and 
30 feet thick, but each is further divided into thinner layers by chlorite 
slate sheets a few inches thick. Some of the ore is strongly magnetic, 
coarsely crystallized, and homogeneous and is broken into cubical 
masses by joint planes, but most of it is a fine-grained grayish black 
mass of magnetite grains and minute octahedrons with a very little 
quartz in the interstices between them. In most of the ore the struc¬ 
ture is sugary, with a slight suggestion of banding. In other specimens 
there is a slight sehistosity and the hand specimens resemble a fine¬ 
grained specular ore. In many places through the ore are shear zones 
marked by chlorite slickensides, and fr quently there are little lenses of 
chlorite embedded in it. Where this is the case there is usually a slick- 
ensided joint extending from the lens. 

Analyses of the ore from this mine show that some specimens are 
magnetite and others mixtures of magnetite and hematite. Analyses 1 
and 3 were made bv Mr. Farrar, and analysis 2 by Dr. Hinds of the Ten- 
nessee Geological Survey. 

Analyses of ore from Finney and Teegarden mine, near Elk Mills, Carter County, Tenn., 


with calculated equivalents of metallic iron, 

magnetite and hematite. 



1 

2 

3 


Sample from 

Beil 

Sperulai 


dump 

ore 

ore 

Silica (SiOo). 


19.94 

21.94 

Alumina (AI 2 O 3 ) . 


.24 

1.26 

Ferric oxide (FeoOa). 

36.57 

26.20 

54.76 

Ferrous oxide (FeO) . 

20.74 


21.52 

Magnetite (Fe 3 04 ). 


53.13 


Manganese oxide (MnO) . 



.06 

Magnesia (MgO). 

.48 

. 26a 

.23 

Lime (CaO). 

.16 

.00 

.24 

Soda (Na 2 0). 

•• .. \ 



Potash (K-.O). 

. ) 

.ola 

.... 

Phosphorus pentoxide (P 2 O 5 ). 


Tr. 

.026 

Titanium dioxide (TiO>). 

.00 

.00 

.... 

Water (FLO). 


.20 




100.48 

100.036 


Metallic iron. 41.73 56.81 55.07 

Magnetite.. 53.20 53.13 69.36 

Hematite^. 26.20 7.20 


a The determinations of M'gO, Na20 and I\ 2 0 were made by Mr. Farrar. 
b. As some of the ferrous iron in all the samples was contributed by silicates, the 
quantity of hematite in them is a little larger than the calculated amounts. 

Thin sections of the “best ore" show crystals and crystal groups 
of an opaque mineral from 1 to 3 mm. in diameter, and large grains of 


































HEMATITIC MAGNETITES 


247 


quartz in a matrix composed mainly of small quartz grains. (Figure 
28.) In this matrix are a few small clumps of hornblende or chlorite 
and a few wisps of other fibrous minerals. Most of the T arger quartz 
grains show an undulous extinction, and nearly all are granulated around 
their edges. The individual grains of the matrix are of about the same 
magnitude as the grains of the granulated material near the large quartz 
grains, but they are completely recrystallized so that they interlock. 
The general arrangement of the ore crystals and groups of crystals is 
roughly parallel. 

The magnetite-chlorite schist on the upper side of the ore is very 
much slickensided and obscurely layered, like a fine-grained slate. 
Under the microscope the alternating layers differ in containing chlorite 



Figure 28. Photomicrograph of hematitic magnetite ore from Finney and Teegarden 
mine, Carter County, Tennessee. Magnified 50 diam. 

and fibrous green hornblende. The chlorite layers contain in addition 
to the chlorite a few grains and crystals of magnetite, a very little inter¬ 
stitial quartz and a little interstitial fluorite. The chlorite is elongated 
in a parallel direction and the magnetite particles are arranged in lines 
in the same direction. In the hornblende layers the hornblende forms 
a meshwork of small fibers. Magnetite is in much greater amount in 
these layers than in the chlorite layers and its grains are elongate per¬ 
pendicular to the layering. The schistosity of the layers is due to the 
arrangement of the lenses of quartz and colorless fluorite in a parallel 
position. 

Other chlorite-magnetite schists contain numerous broken plagio- 
clase and quartz grains and crystals of magnetite in a schistose matrix 


248 


MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


consisting of bundles of hornblende in a fine-grained mass of quartz, 
feldspar and chlorite. The hornblende winds around larger grains and 
between lenticular masses of the fine-grained aggregate, producing 
under the microscope an appearance resembling that of the “augen” 
structure of many gneisses. The magnetite is in groups of sharply 
defined crystals, many of which are fractured. These schists are ap¬ 
parently basic igneous rocks into which magnetite and fluorite have been 
injected. 

A “blue slate,” which, according to Hamilton, is 20 feet above the 
ore, is so thoroughly sheared and slickensided that it is fissile. The 
slate is thinly banded in dark and light layers—the darker ones being 
like the chlorite schists in contact with the ore and the lighter ones 
consisting of comparatively large fragments of granulated quartz in a 
mosaic of finely crushed quartz lenses, separated from one another by 
thin seams of chlorite or hornblende. Through this mass are thin lenses 
rich in fibers of a brightly polarizing, light-green mineral that may be 
kaolin. The rock is so completely crushed and sheared that no hints 
of its original structures remain. An analysis by Dr. Hinds gave the 
results below: 


Partial analysis of blue slate above ore at Finney and Teegarden mine, Carter County, N . C. 


Silica (Si0 2 ). 50.16 

Alumina (A1 2 0 3 ). 19.83 

Ferric oxide (Fe 2 0 3 ). 1 20 63 

Ferrous oxide (FeO). > 

Magnesia (MgO). 1.68 

Lime (CaO). 1.26 

Baryta (BaO).11 


Soda (Na 2 0) . Tr- 

Potash (K 2 0). Tr* 

Water at 110° (H 2 0). .40 

Water above 110° (H 2 0). 3.34 

Phosphorus pentoxide (P 2 0 5 ).92 

Sulphur trioxide (S0 3 ). .69 


Special determinations of ferrous and ferric iron were made in an¬ 
other specimen from the same place by Mr. Farrar, who found: Silica 
(Si0 2 ), 57.08 per cent; ferrous oxide (FeO), 16.22 per cent, and 
ferric oxide, 1.39 per cent. The quantity of magnetite present is about 
2.09 per cent. 

Between the slaty rocks and the gneissic country rock are layers of 
white and of gray, extremely fine-grained rocks closely resembling in 
appearance slightly schistose felsites. All of them are imperfectly 
slickensided and all are distinctly jointed. Mr. Hamilton has named 
the three most easily distinguished phases “white rock,” “whet rock,” 
and “blue eruptive.” An analysis of each of these is recorded below. 
The first was made by Dr. Hinds and the second and third by Mr. 
Farrar of the Tennessee Geological Survey. 














HEMATITIC MAGNETITES 


249 


Analyses of igneous rocks associated with ore at the Finney and Teegarden mine. Carter 


County, 

Tennessee. 

White 

Wbet 

Blue 


rock 

rock 

eruptive 

Silica (SiOo). 

73.78 

76.60 

60.92 

Alumina (A1>0 3 ). 

13.96 

11.98 

19.22 

Ferric oxide (Feo0 3 ). 

.80 

.27 

5.40 

Ferrous oxide (FeO). 

1.30 

2.72 

4.09 

Magnesia (MgO). 


.36 

.26 

Lime (CaO). 

2.08 

.52 

.48 

Soda (Na>0). 

1.45 

4.09 

7.75 

Potash (KoO). 

5.58 

2.20 

1.55 

Phosphorus pentoxide (P 2 O 5 ). 

.53 

.017 

Tr. 

Water above 110 ° (H 2 0) . . . . 

.50 

.70 

.... 

Titanium dioxide (TiO>). 

• • • • 

.00 

.... 

Fluorine (F). 

2.19a 

.... 

.81 


102.17 99.457 100.35 

LessO = F . .92 .... .34 


101.25 99.457 100.01 

a. The determination of fluorine was made by Mr. Farrar on a different specimen 
from that analyzed by Dr. Hinds. 


The corresponding norms of these rocks are as shown below. That 
of the “white rock” is only approximate, as the fluorine was determined 
on •a different sample from that which furnished the determinations of 
the other components. The corrections are the percentages of calcium, 
in excess of the quantities reported in the analyses, that it was necessary 
to assume for combination with all the fluorine and all the phosphorus 
pentoxide present to make fluorite and apatite. 


Mineral composition of igneous rocks calculated from above analyses. 



White 

Whet 

Blue 


rock 

rock 

eruptive 

Quartz. 

42.72 

40.80 

8.04 

Orthoclase. 

33.36 

12.79 

9.45 

Albite. 

12.58 

34.58 

65.50 

Anorthite. 


2.50 


Corundum. 

5.30 

2.04 

4.69 

Magnetite. 

1.16 

.46 

7.89 

Apatite. 

1 34 

- • • • 

.... 

Hypersthene. 

1.72 

5.65 

3.64 

Water. 

.50 

.70 

.... 

Fluorite. 

4.45 

.... 

1.64 


103.13 

99.52 

100.85 

Correction. 

1.23 

.... 

.48 


101.90 

99.52 

100.37 


In terms of the chemical classification the “white rock" is a dopo- 
tassic alaskase, or a magdeburgose, the “whet rock," a dosodic alaskase 
and the “blue eruptive” a persodic umptekase, or a kirunose. The 






























250 MAGNETIC IRON ORES OF EAST TENN. ANI) WESTERN N. C. 

exclusion of fluorite from the “white rock’' would not change its place 
in the classification, but the exclusion of the fluorite and magnetite 
from the “blue eruptive” would place it with the persodic nordmarkase, 
or tuolumnose. 

The “white rock” is very fine-grained, snow-white and massive. 
It is crossed by joint cracks and exhibits a very obscure layering. In 
thin section it shows large fragments of quartz and groups of quartz 
fragments and a few large feldspar fragments in a matrix of quartz and 
feldspar grains measuring about 0.04 to 0.06 millimeters in diameter. 
The larger quartz pieces are granulated and the larger feldspars are 
cracked. Both minerals exhibit strain shadows. Quartz and feld¬ 
spars compose the greater part of the matrix and all the grains appear 
as though they were crushed fragments. Fluorite is always present as 
a filling of interstices. A few small flakes of green mica and green 
hornblende, a few tiny plates of chlorite and a rare speck of magnetite 
are the only other components noticeable. The white rock is a rhy¬ 
olite or an aplite that was sheared and later filled with fluorite. 

The “whet rock” is a faintly schistose, fine-grained ash-gray rock 
containing here and there little specks of quartz. Under the micro¬ 
scope the rock is seen to consist of a few round grains of quartz and 
broken splinters of plagioclase from about 0.3 to 5 millimeters in diam¬ 
eter, in a matrix of quartz and feldspar grains, with an almost uniform 
diameter of about 0.01 millimeter, a few small flakes of green hornblende 
and biotite, and tiny plates of muscovite or kaolinite. The hornblende 
and biotite flakes are of about the same sizes as the quartz and feldspar. 
Most of the components of the matrix are equidimensional, but many 
groups of quartz or feldspar grains form little flat lenses that lie with 
their longer dimensions in the same plane, and many of the hornblende 
and biotite plates are arranged in a similar position. This parallel 
orientation of the lenses, the hornblende and the biotite produce a 
slight schistosity. The rock is apparently a crushed and partly recrys¬ 
tallized soda rhyolite. 

The “blue eruptive” is very much like the whet rock. It is finer 
grained, more massive, and is dove-colored. In the hand specimen it 
resembles very closely a gray chert. The thin section shows a mottled 
aggregate of quartz and feldspar grains and fibers and plates of a light 
green and colorless micaceous mineral that may be sericite or kaolinite. 
The average diameter of the grains is 0.005 millimeter. The mottling 
is due to the presence of little lenses of quartz or of feldspar grains in the 
midst of a uniformly granular matrix. The micaceous components form 
wisps which wind sinuously through the matrix and surround the little 
lenses. A few clumps of broken sphene grains scattered through the 
matrix are the only other components recognizable. The lenses and 
the micaceous minerals are elongated in the same direction producing a 


HEMATITIC MAGNETITES 


251 


schistosity which is very distinct in the slide, though hardly noticeable 
in the hand specimen. 

A coarser grained variety of the same rock, according to Hamilton, 
is closely associated with the ore-body 264 It is much jointed and the 
vails of its joint cracks are coated with very dark green biotite. In 
thin section the rock is like that last described except that it is coarser 
grained. It shows an interlocking aggregate of plagioclase, orthoclase 
and a few quartz grains with average diameters of from 0.2 to 0.4 milli¬ 
meter forming a matrix surrounding a few larger microperthitic feld¬ 
spars, some of which have diameters of 1 millimeter. Tiny masses of 
colorless fluorite fill the interstices between the grains of the matrix. 
In some places the fluorite particles are arranged in lines as though form¬ 
ing tiny veins but the greater part of the mineral is distributed uniformly 
through the section. The only dark components are groups of magne¬ 
tite crystals. Most of the crystals occur between the feldspar grains, 
but they are particularly numerous in and around the larger fluorite 
masses. Y\ here the magnetite and fluorite are in contact the fluorite 
is violet. The whole section is besprinkled with dust particles which 
under high powers are resolved into tiny plates of amphibole, glass 
inclusions and little colorless prisms too small to be identified. The 
rock is an albitic or a very sodic trachyte, into which fluorite and mag¬ 
netite have been forced. The blue eruptives are to be classed, probably, 
with Keith’s metarhyolites 2 65 , which are thought to be of Algonkian age. 

ORIGIN 

There is not much evidence as to the source of the hematitic mag¬ 
netite ore layers. As, however, the iron oxides are closely associated 
with the chloritic and rhyolitic layers, and the ore and chloritic rock 
grade into one another it is reasonable to suppose that the ore and 
rocks are genetically connected. The general presence of fluorite in 
the layered rocks suggests the presence of emanation of fluorine or 
fluorides from a subterranean magma. This emanation may have 
risen after the intrusion of the rhyolites and trachyte into the country 
rock and it may have been accompanied by intrusions more basic than 
the earlier ones, giving rise to what are now the chlorite schists and the 
“blue slates." With these came the iron oxides in the form of magne¬ 
tite, some of which was later changed to martite, or it is even conceiv¬ 
able that some of the oxides were magnetite and others hematite, since 
in a few cases hematite alone is known to occur in veins cutting the 
schistose country rock. Clarke 2 66 calls attention to the fact that ferric 
oxide can crystallize from magmas as hematite only when ferrous com¬ 
pounds are either absent or present in quite subordinate amounts, for 

261 UnpubIished report to the Tennessee Geologic Survey. 

266 Keith, Arthur, U. S. Geol. Survey Geol. Atlas, Cranberry folio (No. 90), 1903. 

266 Clarke, F. W., The data of geochemistry: U. S. Geol. Survey Bull. 616, p. 347, 1916’ 



MAGNETIC IRON ORES OF EAST TENN. AND WESTERN N. C. 


2 52 


ferrous oxide unites with it to form magnetite. Magnetite appears 
more commonly in rocks rich in ferromagnesian minerals, while hema¬ 
tite appears chiefly in more acidic, alkaline rocks like rhyolites and 
trachytes. It is possible that, in the present case, the fluorine tended 
to change some of the FeO into Fe 2 0 3 , as it is well known that, under 
some conditions, chlorine and fluorine may act as oxidizers. 207 How¬ 
ever much of the ferrous iron there may have been originally, it is pos¬ 
sible that enough was oxidized through the fluorine or fluorides to fur¬ 
nish an excess of Fe 2 0 3 which solidified as hematite. 

Because the associations of the more common magnetites like those 
at Cranberry, the Wilder mine, etc., are different from those of the Finney 
and Teegarden mine, it is inferred that the sources of the two kinds of 
ores were different. While both are thought to be of magmatic origin, 
the Cranberry ore is believed to have been brought into its present 
position by pegmatites and the emanations accompanying them, and 
the ore of the Finney and Teegarden mine to have been brought up by 
basic phases of the magmas, the earlier intrusions of which were the 
rhyolites. Following the advent of the magmas came emanations of 
iron compounds and fluorine. In both cases the intrusions followed 
zones of weakness in the country rock and in both cases they were 
folded with the country rock by later deformations. 

RESERVES 

There is very little evidence upon which to base an assertion as 
to the economic value of the hematitic magnetite ore. In most places 
seen, the deposits are too small to warrant consideration as sources of 
ore. Those on the belt in the valley of Lunsford Branch are the largest 
known, but they are so inconveniently situated with respect to trans¬ 
portation that it will be a long time before they can be worked profit¬ 
ably. So far as can now be judged, without a great deal of additional 
exploration, the quantity of ore in the belt is not sufficient to warrant 
the building of a branch from the railroads at Butler or Shell Creek. 
The ore is of good quality, but there is not likely to be more than 65,000 
tons of merchantable grade within 500 feet of the surface for each 1,000 
feet of the length of the belt. 


267 Compare: The paragenesis of martite and magnetite of the Mesabi range, by Dr. D. 
H. Newland: Econ. Geol., vol. 17, p. 301, 1922. 

































































































■ 














































' 


































































, 

V 
























* 






« 
































